Coronary Artery Disease

Coronary artery disease; Arteriosclerotic heart disease; CHD; CAD
Definition
Coronary heart disease (CHD) is a narrowing of the small blood vessels that supply blood and oxygen to the heart. CHD is also called coronary artery disease.
Causes
Coronary heart disease is usually caused by a condition called atherosclerosis, which occurs when fatty material and a substance called plaque builds up on the walls of your arteries. This causes them to get narrow. As the coronary arteries narrow, blood flow to the heart can slow down or stop, causing chest pain (stable angina), shortness of breath, heart attack, and other symptoms.
Coronary heart disease (CHD) is the leading cause of death in the United States for men and women. According to the American Heart Association, more than 15 million people have some form of the condition.
Men in their 40s have a higher risk of CHD than women. But, as women get older, their risk increases so that it is almost equal to a man's risk. See: Heart disease and women
Many things increase your risk for CHD. Bad genes (heredity) can increase your risk. You're more likely to develop the condition if someone in your family has had it -- especially if they had it before age 50. Your risk for CHD goes up the older you get.
The following factors also increase your risk of CHD:
Diabetes
High blood pressure
High LDL "bad" cholesterol
Low HDL "good" cholesterol
Menopause
Not getting enough physical activity or exercise
Obesity
Smoking
Higher-than-normal levels of inflammation-related substances may also increase your risk for a heart attack. Such substances include C-reactive protein and fibrinogen. Increased levels of a chemical called homocysteine, an amino acid, are also linked to an increased risk of a heart attack.
Symptoms
Symptoms may be very noticeable, but sometimes you can have the disease and not have any symptoms.
Chest pain or discomfort (angina) is the most common symptom. You feel this pain when the heart is not getting enough blood or oxygen. How bad the pain is varies from person to person.
There are two main types of chest pain:
Atypical chest pain -- often sharp and comes and goes. You can feel it in your left chest, abdomen, back, or arm. It is unrelated to exercise and not relieved by rest or a medicine called nitroglycerin. Atypical chest pain is more common in women.
Typical chest pain -- feels heavy or like someone is squeezing you. You feel it under your breast bone (sternum). The pain usually occurs with activity or emotion, and goes away with rest or a medicine called nitroglycerin.
Adults with typical chest pain have a higher risk of CHD than those with atypical chest pain.
Other symptoms include:
Shortness of breath
Heart attack -- in some cases, the first sign of CHD is a heart attack
Exams and Tests
Many tests help diagnose CHD. Usually, your doctor will order more than one test before making a definite diagnosis.
Tests may include:
Electrocardiogram (ECG)
Exercise stress test
Echocardiogram
Nuclear scan
Coronary angiography/arteriography
Electron-beam computed tomography (EBCT) to look for calcium in the lining of the arteries -- the more calcium, the higher your chance for CHD
Coronary CT angiography
Magnetic resonance angiography
Treatment
Treatment depends on your symptoms and how severe the disease is.
If you have coronary artery disease that does not cause symptoms, you can be treated with either medicine or angioplasty with stenting. Recent studies show that medicine and angioplasty with stenting have equal benefits. Angioplasty with stenting does not help you live longer, but it can reduce angina or other symptoms of CHD.
Angioplasty with stenting, however, can be a life-saving procedure if you are having a heart attack.
Medications used to treat CHD include:
ACE inhibitors to lower blood pressure
Blood thinners (antiplatelet drugs) to reduce your risk of blood clots
Beta-blockers to lower heart rate, blood pressure, and oxygen use by the heart
Calcium channel blockers to relax arteries, lowering blood pressure and reducing strain on the heart
Diuretics to lower blood pressure
Nitrates (such as nitroglycerin) to stop chest pain and improve blood supply to the heart
Statins to lower cholesterol
Procedures to treat and diagnose CHD are called percutaneous coronary interventions, or PCIs. Angioplasty and stenting are types of PCIs. Other types include:
Coronary atherectomy
Coronary radiation implant or coronary brachytherapy
Coronary brachytherapy delivers radiation into the coronary arteries. This treatment is only for patients who have had a stent-related problems.
Surgeries used to treat CHD include:
Coronary artery bypass surgery
Minimally invasive heart surgery
Lifestyle changes are very important. Your doctor may tell you to:
Avoid or reduce the amount of salt (sodium) you eat
Eat a heart healthy diet -- one that is low in saturated fats, cholesterol, and trans fat
Get regular exercise and maintain a healthy weight
Keep your blood sugar strictly under control if you have diabetes
Stop smoking
Prognosis
Everyone recovers differently. Some people can maintain a healthy life by changing their diet, stopping smoking, and taking medications exactly as the doctor prescribes. Others may need medical procedures such as angioplasty or surgery.
Although everyone is different, early detection of CHD generally results in a better outcome.
Possible Complications
Heart attack
Heart failure
Unstable angina
Sudden death
When to Contact a Medical Professional
If you have any of the risk factors for CHD, set up an appointment with your doctor to discuss prevention and possible treatment.
If you have angina, shortness of breath, or symptoms of a heart attack, immediately contact your health care provider, call the local emergency number (such as 911), or go to the emergency room.
Prevention
See your health care provider regularly. Tips for preventing CHD or lowering your risk of the disease:
Avoid or reduce stress as best as you can.
Don't smoke.
Eat well-balanced meals that are low in fat and cholesterol and include several daily servings of fruits and vegetables.
Get regular exercise. If your weight is considered normal, get at least 30 minutes of exercise every day. If you are overweight or obese, experts say you should get 60 to 90 minutes of exercise every day.
Keep your blood pressure, blood sugar, and cholesterol under control.
Moderate amounts of alcohol (1 glass a day for women, 2 for men) may reduce your risk of cardiovascular problems. However, drinking larger amounts does more harm than good.
If you have one or more risk factors for coronary heart disease, talk to your doctor about possibly taking an aspirin a day to help prevent a heart attack or stroke. Low-dose aspirin therapy may be prescribed if the benefit is likely to outweigh the risk of gastrointestinal side effects.
New guidelines no longer recommend hormone replacement therapy, vitamins E or C, antioxidants, or folic acid to prevent heart disease.
References
Mosca L, Banka CL, Benjamin EJ, et al. Evidence-Based Guidelines for Cardiovascular Disease Prevention in Women: 2007 Update. Circulation. 2007; Published online before print February 19, 2007.
Smith SC Jr, Allen J, Blair SN, et al. AHA/ACC guidelines for secondary prevention for patients with coronary and other atherosclerotic vascular disease: 2006 update: endorsed by the National Heart, Lung, and Blood Institute. Circulation. 2006 May 16;113(19):2363-72. Erratum in: Circulation. 2006 Jun 6;113(22):e847.
Boden WE, O'rourke RA, Teo KK, et al. Optimal Medical Therapy with or without PCI for Stable Coronary Disease. N Engl J Med. 2007 Mar 26; [Epub ahead of print].
American Heart Association. Heart Disease and Stroke Statistics — 2007 Update. Dallas, Texas: American Heart Association; 2007

Diabetes

Definition
Diabetes is a life-long disease marked by high levels of sugar in the blood.
Causes
Diabetes can be caused by too little insulin (a hormone produced by the pancreas to control blood sugar), resistance to insulin, or both.
To understand diabetes, it is important to first understand the normal process of food metabolism. Several things happen when food is digested:
A sugar called glucose enters the bloodstream. Glucose is a source of fuel for the body.
An organ called the pancreas makes insulin. The role of insulin is to move glucose from the bloodstream into muscle, fat, and liver cells, where it can be used as fuel.
People with diabetes have high blood sugar. This is because their pancreas does not make enough insulin or their muscle, fat, and liver cells do not respond to insulin normally, or both.
There are three major types of diabetes:
Type 1 diabetes is usually diagnosed in childhood. The body makes little or no insulin, and daily injections of insulin are needed to sustain life.
Type 2 diabetes is far more common than type 1 and makes up most of all cases of diabetes. It usually occurs in adulthood. The pancreas does not make enough insulin to keep blood glucose levels normal, often because the body does not respond well to the insulin. Many people with type 2 diabetes do not know they have it, although it is a serious condition. Type 2 diabetes is becoming more common due to the growing number of older Americans, increasing obesity, and failure to exercise.
Gestational diabetes is high blood glucose that develops at any time during pregnancy in a woman who does not have diabetes.
Diabetes affects more than 20 million Americans. About 54 million Americans have prediabetes. There are many risk factors for diabetes, including:
A parent, brother, or sister with diabetes
Obesity
Age greater than 45 years
Some ethnic groups (particularly African Americans, Native Americans, Asians, Pacific Islanders, and Hispanic Americans)
Gestational diabetes or delivering a baby weighing more than 9 pounds
High blood pressure
High blood levels of triglycerides (a type of fat molecule)
High blood cholesterol level
Not getting enough exercise
The American Diabetes Association recommends that all adults over age 45 be screened for diabetes at least every 3 years. A person at high risk should be screened more often.
Symptoms
High blood levels of glucose can cause several problems, including frequent urination, excessive thirst, hunger, fatigue, weight loss, and blurry vision. However, because type 2 diabetes develops slowly, some people with high blood sugar experience no symptoms at all.
Symptoms of type 1 diabetes:
Increased thirst
Increased urination
Weight loss in spite of increased appetite
Fatigue
Nausea
Vomiting
Patients with type 1 diabetes usually develop symptoms over a short period of time, and the condition is often diagnosed in an emergency setting.
Symptoms of type 2 diabetes:
Increased thirst
Increased urination
Increased appetite
Fatigue
Blurred vision
Slow-healing infections
Impotence in men
Exams and Tests
A urine analysis may be used to look for glucose and ketones from the breakdown of fat. However, a urine test alone does not diagnose diabetes. The following blood glucose tests are used to diagnose diabetes:
Fasting blood glucose level -- diabetes is diagnosed if higher than 126 mg/dL on two occasions. Levels between 100 and 126 mg/dl are referred to as impaired fasting glucose or pre-diabetes. These levels are considered to be risk factors for type 2 diabetes and its complications.
Random (non-fasting) blood glucose level -- diabetes is suspected if higher than 200 mg/dL and accompanied by the classic symptoms of increased thirst, urination, and fatigue. (This test must be confirmed with a fasting blood glucose test.)
Oral glucose tolerance test -- diabetes is diagnosed if glucose level is higher than 200 mg/dL after 2 hours (This test is used more for type 2 diabetes.)
You should also ask your doctor how often to you need your hemoglobin A1c (HbA1c) level checked. The HbA1c is a measure of average blood glucose during the previous 2 to 3 months. It is a very helpful way to determine how well treatment is working.
Ketone testing is another test that is used in type 1 diabetes. Ketones are produced by the breakdown of fat and muscle, and they are harmful at high levels. The ketone test is done using a urine sample. High levels of blood ketones may result in a serious condition called ketoacidosis. Ketone testing is usually done at the following times:
When the blood sugar is higher than 240 mg/dL
During acute illness (for example, pneumonia, heart attack, or stroke)
When nausea or vomiting occur
During pregnancy
Treatment
There is no cure for diabetes. Treatment involves medicines, diet, and exercise to control blood sugar and prevent symptoms and complications.
LEARN THESE SKILLS
Basic diabetes management skills will help prevent the need for emergency care. These skills include:
How to recognize and treat low blood sugar (hypoglycemia) and high blood sugar (hyperglycemia)
What to eat and when
How to take insulin or oral medication
How to test and record blood glucose
How to test urine for ketones (type 1 diabetes only)
How to adjust insulin or food intake when changing exercise and eating habits
How to handle sick days
Where to buy diabetes supplies and how to store them
After you learn the basics of diabetes care, learn how the disease can cause long-term health problems and the best ways to prevent these problems. People with diabetes need to review and update their knowledge, because new research and improved ways to treat diabetes are constantly being developed.
SELF-TESTING
If you have diabetes, your doctor may tell you to regularly check your blood sugar levels at home. There are a number of devices available, and they use only a drop of blood. Self-monitoring tells you how well diet, medication, and exercise are working together to control your diabetes and can help your doctor prevent complications.
The American Diabetes Association recommends that premeal blood sugar levels fall in the range of 80 to 120 mg/dL and bedtime blood levels fall in the range of 100 to 140 mg/dL. Your doctor may adjust this depending on your circumstances.
WHAT TO EAT
You should work closely with your health care provider to learn how much fat, protein, and carbohydrates you need in your diet. A registered dietician can be very helpful in planning dietary needs.
People with type 1 diabetes should eat at about the same times each day and try to be consistent with the types of food they choose. This helps to prevent blood sugars from becoming extremely high or low.
Persons with type 2 diabetes should follow a well-balanced and low-fat diet.
HOW TO TAKE MEDICATION
Medications to treat diabetes include insulin and glucose-lowering pills called oral hypoglycemic drugs.
Persons with type 1 diabetes cannot make their own insulin, so daily insulin injections are needed. Insulin does not come in pill form. Injections that are generally needed one to four times per day. Some people use an insulin pump, which is worn at all times and delivers a steady flow of insulin throughout the day. Other people may use a new type of inhaled insulin.
Insulin preparations differ in how quickly they start to work and how long they remain active. Sometimes different types of insulin are mixed together in a single injection. The types of insulin to use, the doses needed, and the number of daily injections are chosen by a health care professional trained to provide diabetes care.
People who need insulin are taught to give themselves injections by their health care providers or diabetes educators.
Unlike type 1 diabetes, type 2 diabetes may respond to treatment with exercise, diet, and medicines taken by mouth. There are several types of medicines used to lower blood glucose in type 2 diabetes. They fall into one of three groups:
Medications called oral sulfonylureas that increase insulin production by the pancreas.
Medications called thiazolidinediones that help increase the cell's sensitivity (responsiveness) to insulin.
Medications that delay absorption of glucose from the gut. These include acarbose and miglitol.
There are some injectable medicines used to lower blood sugar. They include exenatide and pramlintide.
Most persons with type 2 diabetes will need more than one medication for good blood sugar control within 3 years of starting their first medication. Different groups of medications may be combined or used with insulin.
Some people with type 2 diabetes find they no longer need medication if they lose weight and increase activity, because when their ideal weight is reached, their own insulin and a careful diet can control their blood glucose levels.
It is unknown if hypoglycemic medicines taken by mouth are safe for use in pregnancy. Women who have type 2 diabetes and take these medications may be switched to insulin during pregnancy and while breastfeeding.
Gestational diabetes is treated with insulin and changes in diet.
EXERCISE
Regular exercise is especially important for people with diabetes. It helps with blood sugar control, weight loss, and high blood pressure. People with diabetes who exercise are less likely to experience a heart attack or stroke than diabetics who do not exercise regularly. You should be evaluated by your physician before starting an exercise program.
Here are some exercise considerations:
Choose an enjoyable physical activity that is appropriate for your current fitness level.
Exercise every day, and at the same time of day, if possible.
Monitor blood glucose levels before and after exercise.
Carry food that contains a fast-acting carbohydrate in case you become hypoglycemic during or after exercise.
Carry a diabetes identification card and a mobile phone or change for a payphone in case of emergency.
Drink extra fluids that do not contain sugar before, during, and after exercise.
Changes in exercise intensity or duration may need changes in diet or medication dose to keep blood sugar levels from going too high or low.
FOOT CARE
People with diabetes are prone to foot problems because of the likelihood of damage to blood vessels and nerves and a decreased ability to fight infection. Problems with blood flow and damage to nerves may cause an injury to the foot to go unnoticed until infection develops. Death of skin and other tissue can occur.
If left untreated, the affected foot may need to be amputated. Diabetes is the most common condition leading to amputations.
To prevent injury to the feet, people with diabetes should adopt a daily routine of checking and caring for the feet as follows:
Check your feet every day, and report sores or changes and signs of infection.
Wash your feet every day with lukewarm water and mild soap, and dry them thoroughly.
Soften dry skin with lotion or petroleum jelly.
Protect feet with comfortable, well-fitting shoes.
Exercise daily to promote good circulation.
See a podiatrist for foot problems or to have corns or calluses removed.
Remove shoes and socks during a visit to your health care provider and remind him or her to examine your feet.
Stop smoking, which hinders blood flow to the feet.
Outlook (Prognosis)
With good blood glucose and blood pressure control, many of the complications of diabetes can be prevented.
Studies have shown that strict control of blood sugar and blood pressure levels in persons with diabetes helps reduce the risk of kidney disease, eye disease, nervous system disease, heart attack, and stroke.
Possible Complications
Emergency complications include diabetic hyperglycemic hyperosmolar coma.
Long-term complications include:
Diabetic retinopathy
Diabetic nephropathy
Diabetic neuropathy
Peripheral vascular disease
Hyperlipidemia, hypertension, atherosclerosis, and coronary artery disease
When to Contact a Medical Professional Return to top
Go to the emergency room or call the local emergency number (such as 911) if symptoms of ketoacidosis occur:
Increased thirst and urination
Nausea
Deep and rapid breathing
Abdominal pain
Sweet-smelling breath
Loss of consciousness
Go to the emergency room or call the local emergency number if symptoms of extremely low blood sugar (hypoglycemic coma or severe insulin reaction) occur:
Weakness
Drowsiness
Headache
Confusion
Dizziness
Double vision
Lack of coordination
Convulsions or unconsciousness
Prevention
Maintaining an ideal body weight and an active lifestyle may prevent the onset of type 2 diabetes. Currently there is no way to prevent type 1 diabetes.
References
Standards of medical care in diabetes--2007. Diabetes Care. Jan 2007;30 Suppl 1:S4-S41.
Larsen PR, Kronberg HM, Schlomo M, et al. Williams Textbook of Endocrinology. 10th ed. St. Louis, Mo: WB Saunders; 2003:1427-1468, 1485-1504.
Armstrong C. ADA Releases Standards of Medical Care for Patients with Diabetes. Am Fam Physician. Sept 2006; 74(5); 871-874.
Caballero E. Prediabetes. J Clin Endocrinol Metab. Jan 2007; 92(1); 15A-16A.

Cancer

Alternative Names
Carcinoma; Malignant tumor Definition Return to top
Cancer is the uncontrolled growth of abnormal cells in
the body. Cancerous cells are also called malignant
cells.
Causes
Cells are the building blocks of living things. Cancer
grows out of normal cells in the body. Normal cells
multiply when the body needs them, and die when the body
doesn't. Cancer appears to occur when the growth of cells
in the body is out of control and cells divide too
rapidly. It can also occur when cells “forget” how to
die.
There are many different kinds of cancers. Cancer can
develop in almost any organ or tissue, such as the lung,
colon, breast, skin, bones, or nerve tissue.
There are multiple causes of cancers, including:
Radiation Sunlight Tobacco Certain viruses Benzene Certain poisonous mushrooms and aflatoxins (a poison
produced by organisms that can grow on peanut plants) However, the cause of many cancers remains unknown.
The most common cause of cancer-related death is lung
cancer.
The three most common cancers in men in the United States
are prostate cancer, lung cancer, and colon cancer. In
women in the U.S., the three most frequently occurring
cancers are breast cancer, lung cancer, and colon cancer.
Certain cancers are more common in particular geographic
areas. For example, in Japan, there are many cases of
gastric cancer, while in the U.S. this type of cancer is
relatively rare. Differences in diet may play a role.
Some other types of cancers include:
Brain cancer Cervical cancer Uterine cancer Liver cancer Leukemia Hodgkin's lymphoma Non-Hodgkin's lymphoma Kidney cancer Ovarian cancer Skin cancer Testicular cancer Thyroid cancer Symptoms Return to top
Symptoms of cancer depend on the type and location of the
tumor. For example, lung cancer can cause coughing,
shortness of breath, or chest pain, while colon cancer
often causes diarrhea, constipation, and blood in the
stool.
Some cancers may not have any symptoms at all. In some
cancers, such as gallbladder cancer, symptoms often are
not present until the disease has reached an advanced
stage.
However, the following symptoms are common with most
cancers:
Fever Chills Night sweats Weight loss Loss of appetite Fatigue Malaise Exams and Tests Return to top
Like symptoms, the signs of cancer vary based on the type
and location of the tumor. Common tests include the
following:
CT scan Complete blood count (CBC) Blood chemistries Biopsy of the tumor Bone marrow biopsy (for lymphoma or leukemia) Chest x-ray Most cancers are diagnosed by biopsy. Depending on the
location of the tumor, the biopsy may be a simple
procedure or a serious operation. Most patients with
cancer undergo CT scans to determine the exact location
of the tumor or tumors.
A cancer diagnosis is difficult to cope with. It is
important, however, that you discuss the type, size, and
location of the cancer with your doctor upon diagnosis.
You also will want to ask about treatment options, along
with their benefits and risks.
It's a good idea to have someone with you at the doctor's
office to help you get through the diagnosis. If you have
trouble asking questions after hearing about your
diagnosis, the person you bring with you can ask them for
you.
Treatment Return to top
Treatment also varies based on the type of cancer and its
stage. The stage of a cancer refers to how much it has
grown and whether the tumor has spread from its original
location.
If the cancer is confined to one location and has not
spread, the goal for treatment would be surgery and cure.
This is often the case with skin cancers. If the tumor has spread to local lymph nodes only,
sometimes these can also be removed. If all of the cancer cannot be removed with surgery, the
options for treatment include radiation, chemotherapy, or
both. Some cancers require a combination of surgery,
radiation, and chemotherapy. Although treatment for cancer can be difficult, there
many ways to keep up your strength.
If you have radiation treatment, know that:
Radiation treatment is painless. Treatment is usually scheduled every weekday. You should allow 30 minutes for each treatment session
although the treatment itself usually takes only a few
minutes. You should get plenty of rest and eat a well-balanced
diet during the course of your radiation therapy. Skin in the treated area may become sensitive and easily
irritated. Side effects of radiation treatment are usually temporary
and vary depending on the area of the body that is being
treated. If you are going through chemotherapy, you should eat
right. Chemotherapy causes your immune system to weaken,
so you should avoid people with colds or the flu. You
should also get plenty of rest, and don't feel you have
to accomplish tasks all at once.
It will help you to talk with family, friends, or a
support group about your feelings. Work with your health
care providers throughout your treatment. Helping
yourself can make you feel more in control.
Support Groups Return to top
The diagnosis of cancer often causes a lot of anxiety and
can affect your entire quality of life. Several support
groups for cancer patients to you cope.
Outlook (Prognosis) Return to top
The outlook varies widely among different types of
cancer. Even among people with one particular type of
cancer, the outcome varies depending on the stage of the
tumor at diagnosis. Some cancers can be cured, some that
are not curable can still be treated well, and some
patients can live for many years with the cancer. Other
tumors are rapidly fatal.
Possible Complications Return to top
One complication is that the cancer may spread. Other
complications vary with the type and stage of the tumor.
When to Contact a Medical Professional Return to top
You should contact your doctor if you develop signs or
symptoms suggestive of cancer.
Prevention Return to top
One of the best ways to prevent cancer is to not smoke or
chew tobacco. Many cancers can be prevented by avoiding
risk factors such as excessive exposure to sunlight and
heavy drinking.
Cancer screenings, such as mammography and breast
examination for breast cancer and colonoscopy for colon
cancer, may help catch these cancers at their early, most
treatable stages. Some people at high risk for developing
certain cancers can take medication to reduce their risk.

Acquired immune deficiency syndrome

Definition
AIDS (Acquired Immune Deficiency Syndrome) is the final and most serious stage of HIV disease, which causes severe damage to the immune system.
According to the Centers for Disease Control and Prevention, AIDS begins when a person with HIV infection has a CD4 cell count below 200. CD4 cells are also called "T-cells" or "helper cells"; they are a type of immune cell. AIDS is also defined by numerous opportunistic infections and cancers that occur in the presence of HIV infection.
Causes
AIDS is the fifth leading cause of death among persons between ages 25 and 44 in the United States, down from number one in 1995. About 25 million people worldwide have died from this infection since the start of the epidemic, and 40.3 million people are currently living with HIV/AIDS globally
Human immunodeficiency virus (HIV) causes AIDS. The virus attacks the immune system and leaves the body vulnerable to a variety of life-threatening infections and cancers.
Common bacteria, yeast, parasites, and viruses that ordinarily do not cause serious disease in people with healthy immune systems can cause fatal illnesses in people with AIDS.
HIV has been found in saliva, tears, nervous system tissue and spinal fluid, blood, semen (including pre-seminal fluid), vaginal fluid, and breast milk. However, only blood, semen, vaginal secretions, and breast milk generally transmit infection to others.
Transmission of the virus occurs:
Through sexual contact -- including oral, vaginal, and anal sex
Through blood -- via blood transfusions (now extremely rare in the U.S) or needle sharing
From mother to child -- a pregnant woman can transmit the virus to her fetus through their shared blood circulation, or a nursing mother can transmit it to her baby in her milk
Other transmission methods are rare and include accidental needle injury, artificial insemination with donated semen, and organ transplants.
HIV infection is not spread by casual contact such as hugging, by touching items previously touched by a person infected with the virus, during participation in sports, or by mosquitoes.
It is not transmitted to a person who DONATES blood or organs. Those who donate organs are not in direct contact with those who receive them. Likewise, a person who donates blood is not in contact with the person receiving it. In all these procedures, sterile needles and instruments are used.
However, HIV can be transmitted to a person RECEIVING blood or organs from an infected donor. This is why blood banks and organ donor programs screen donors, blood, and tissues thoroughly.
Those at highest risk include:
Persons engaging in unprotected sex
Sexual partners of those who participate in high-risk activities (such as anal sex)
Intravenous drug users who share needles
Infants born to mothers with HIV who don't receive HIV therapy during pregnancy
People who received blood transfusions or clotting products between 1977 and 1985 (prior to the beginning standard screening for the virus in the blood)
AIDS begins with HIV infection. People infected with HIV may have no symptoms for ten years or longer, but they can still transmit the infection to others during this symptom-free period. Meanwhile, if the infection is not detected and treated, the immune system gradually weakens, and AIDS develops.
Acute HIV infection progresses over time to asymptomatic HIV infection and then to early symptomatic HIV infection. Later, it progresses to AIDS (defined as very advanced HIV infection with T-cell count below 200).
Most individuals infected with HIV, if not treated, will develop AIDS. There is a small group of patients who develop AIDS very slowly, or never at all. These patients are called non-progressors, and many seem to have a genetic difference that prevents the virus from attaching to certain immune receptors.
Symptoms
The symptoms of AIDS are primarily the result of infections that do not normally develop in individuals with healthy immune systems. These are called opportunistic infections.
Patients with AIDS have had their immune system depleted by HIV and are very susceptible to such opportunistic infections. Common symptoms are fevers, sweats (particularly at night), swollen glands, chills, weakness, and weight loss.
See the signs and tests section below for a list of common opportunistic infections and major symptoms associated with them.
Note: Initial infection with HIV can produce no symptoms. Most people, however, do experience flu-like symptoms with fever, rash, sore throat, and swollen lymph nodes, usually two weeks after contracting the virus. Some people with HIV infection remain without symptoms for years between the time of exposure and development of AIDS.
Exams and Tests
The following is a list of AIDS-related infections and cancers that people with AIDS acquire as their CD4 count decreases. Previously, having AIDS was defined as having HIV infection and getting one of these additional diseases. Now it is additionally defined as a CD4 count below 200, even without an opportunistic infection. Many other illnesses and corresponding symptoms may develop in addition to those listed here.
Common with CD4 count below 350 cells/ml:
Herpes simplex virus -- causes ulcers/vesicles in the mouth or genitals, occurring more frequently and more severely in an HIV-infected patient than before HIV infection
Tuberculosis -- infection by the tuberculosis bacteria that predominately affects the lungs, but can affect other organs such as the bowel, lining of the heart or lungs, brain, or lining of the central nervous system
Oral or vaginal thrush -- yeast infection of the mouth or genitals
Herpes zoster (Shingles) -- ulcers/vesicles over a discrete patch of skin caused by the varicella zoster virus
Non-Hodgkin's lymphoma -- cancer of the lymph glands
Kaposi's sarcoma -- Cancer of the skin, lungs, and bowel, associated with a herpes virus (HHV-8). Can occur at any CD4 count, but more likely at lower CD4 counts, and more common in men than women
CD4 count below 200 cells/ml
Pneumocystis carinii pneumonia, "PCP pneumonia," now called Pneumocystic jiroveci pneumonia
Candida esophagitis -- painful yeast infection of the esophagus
Bacillary angiomatosis -- Skin lesions caused by a bacteria called Bartonella, which is usually acquired from cat scratches
CD4 count below 100 cells/ml
Cryptococcal meningitis -- infection of the lining of the brain by a yeast
AIDS dementia -- worsening and slowing of mental function, caused by HIV itself
Toxoplasmosis encephalitis -- infection of the brain by a parasite, which is frequently found in cat feces; causes discrete lesions in the brain
Progressive multifocal leukoencephalopathy -- a viral disease of the brain caused by a virus (called the JC virus) that results in a severe decline in cognitive and motor functions
Wasting syndrome -- extreme weight loss and loss of appetite, caused by HIV
Cryptosporidium diarrhea -- Extreme diarrhea caused by one of several related parasites
CD4 count below 50/ml
Mycobacterium avium -- a blood infection by a bacterium related to tuberculosis
Cytomegalovirus infection -- a viral infection that can affect almost any organ system, especially the large bowel and the eyes
In addition to the CD4 count, HIV RNA load, and basic screening lab tests, regular vaginal Pap smears are important to monitor in HIV infection, due to the increased risk of cervical cancer in immunocompromised patients. . Anal Pap smears to detect potential cancers may also be important in both HIV infected men and women.
Treatment
There is no cure for AIDS at this time. However, a variety of treatments are available that can delay the progression of disease for many years, and improve the quality of life of those who have developed symptoms.
Antiretroviral therapy suppresses the replication of the HIV virus in the body. A combination of several antiretroviral agents, termed highly active antiretroviral therapy (HAART), has been highly effective in reducing the number of HIV particles in the blood stream, as measured by a blood test called the viral load. This can help the immune system recover from the HIV infection and improve T-cell counts.
Although not a cure for HIV, and people on HAART with suppressed levels of HIV can still transmit the virus to others through sex or sharing of needles, these treatments have been enormously effective for the past ten years. There is good evidence that if the levels of HIV remain suppressed and the CD4 count remains high (above 200), life can be significantly prolonged and improved. However, HIV may become resistant to HAART in patients who do not take their medications on schedule every day. Genetic tests are now available to determine whether a particular strain is resistant to a particular drug -- these may be useful in determining the best drug combination, and adjusting the regimen if it starts to fail. These tests should be performed for any failing treatment course, and prior to starting therapy.
When HIV becomes resistant to HAART, salvage therapy is required, to try to suppress the resistant strain of HIV. Different combinations of medications are used to try to reduce viral load, and there are a variety of new drugs coming out on the market for the treatment of drug-resistant HIV.
Treatment with HAART is not without complications. HAART is a collection of different medications, each with its own side effects. Some common side effects are nausea, headache, weakness, malaise, and fat accumulation on the back and abdomen ("buffalo hump"). When used long-term, these medications increase the risk of heart attack by affecting fat breakdown, specifically through increasing lipids and glucose levels.
Any doctor prescribing HAART should carefully follow the patient for possible side effects associated with the combination of medications the patient takes. In addition, routine blood tests measuring CD4 counts and HIV viral load (a blood test that measures how much virus is in the blood) should be taken every three to four months. The goal is to get the CD4 count as close to normal as possible, and to suppress the HIV viral load to an undetectable level.
Other antiviral agents are in investigational stages and many new drugs are in development. In addition, growth factors that stimulate cell growth, such as Epogen (erthythropoetin) and G-CSF are sometimes used to treat anemia and low white blood cell counts associated with AIDS.
Medications are also used to prevent opportunistic infections (such as Pneumocystis carinii pneumonia) if the CD4 count is low enough. This keeps AIDS patients healthier for longer periods of time. Opportunistic infections are treated as they occur.
Support Groups
Joining support groups where members share common experiences and problems can often help the emotional stress of devastating illnesses.
Outlook (Prognosi)
At the present time, there is no cure for AIDS. It is always fatal if no treatment is provided. In the U.S., most patients survive many years following diagnosis because of the availability of HAART. HAART has dramatically increased the time from diagnosis to death, and research continues in the areas of drug treatments and vaccine development. Unfortunately, HIV medications are not always available in the developing world, where the bulk of the epidemic is raging, due to socioeconomic reasons.
Possible Complications
When a person is infected with HIV, the virus slowly begins to destroy that person's immune system. How fast this occurs differs in each individual. Treatment with HAART can help slow and even halt the destruction of the immune system.
Once the immune system is severely damaged, that person has AIDS, and is now susceptible to infections and cancers that most healthy adults would not get. However, antiretroviral treatment can still be very effective, even at that stage of illness.
When to Contact a Medical Professional
Call for an appointment with your health care provider if you have any of the risk factors for HIV infection, or if symptoms of AIDS are present. By law, AIDS testing must be kept confidential. Your health care provider will review results of your testing with you.
Prevention
See the article on safe sex to learn how to reduce the chance of acquiring or spreading HIV, and other sexually transmitted diseases.
Try not to use intravenous drugs. If IV drugs are used, do not share needles or syringes. Many communities now have needle exchange programs, where used syringes can be disposed of and new, sterile needles obtained for free. These programs can also provide referrals to addiction treatment.
Avoid contact with another person's blood when the HIV status of the bleeding individual is unknown. Protective clothing, masks, and goggles may be appropriate when caring for people who are injured.
Anyone who tests positive for HIV can pass the disease to others and should not donate blood, plasma, body organs, or sperm. An infected person should warn any prospective sexual partner of their HIV-positive status, should not exchange body fluids during sexual activity, and should use whatever preventive measures (such as condoms) will afford the partner the most protection.
HIV-positive women who wish to become pregnant should seek counseling about the risk to unborn children, and medical advances which may help prevent the fetus from becoming infected. Use of certain medications can dramatically reduce the chances that the baby will become infected during pregnancy.
Mothers who are HIV-positive should not breast feed their babies.
Safe-sex practices, such as latex condoms, are highly effective in preventing HIV transmission. HOWEVER, there remains a risk of acquiring the infection even with the use of condoms, if the condom breaks. Abstinence is the only sure way to prevent sexual transmission of HIV.
The riskiest sexual behavior is unprotected receptive anal intercourse -- the least risky sexual behavior is receiving oral sex. Performing oral sex on a man is associated with some risk of HIV transmission, but this is less risky than unprotected vaginal intercourse. Female-to-male transmission of the virus is much less likely than male-to-female transmission. Performing oral sex on a woman who does not have her period carries low risk of transmission.
HIV-positive patients who are taking anti-retroviral medications are less likely to transmit the virus. For example, pregnant women who are on effective treatment at the time of delivery with undetectable viral loads transmit HIV to the infant <1%>