2 Temmuz 2011 Cumartesi
Most countries face high and increasing rates of cardiovascular disease. Each year, heart disease kills more Americans than cancer. In recent years, cardiovascular risk in women has been increasing and has killed more women than breast cancer. A large histological study (PDAY) showed vascular injury accumulates from adolescence, making primary prevention efforts necessary from childhood.
By the time that heart problems are detected, the underlying cause (atherosclerosis) is usually quite advanced, having progressed for decades. There is therefore increased emphasis on preventing atherosclerosis by modifying risk factors, such as healthy eating, exercise and avoidance of smoking.
Arthritis is the most common disease that affects bones in your knees. The cartilage in the knee gradually wears away, causing pain and swelling. Injuries to ligaments and tendons also cause knee problems. A common injury is to the anterior cruciate ligament (ACL). You usually injure your ACL by a sudden twisting motion. ACL and other knee injuries are common sports injuries.
Treatment of knee problems depends on the cause. In some cases your doctor may recommend knee replacement.
Tuberculosis (TB) is a bacterial infection caused by a germ called Mycobacterium tuberculosis. The bacteria usually attack the lungs, but they can also damage other parts of the body. TB spreads through the air when a person with TB of the lungs or throat coughs, sneezes or talks. If you have been exposed, you should go to your doctor for tests. You are more likely to get TB if you have a weak immune system.
Symptoms of TB in the lungs may include
- A bad cough that lasts 3 weeks or longer
- Weight loss
- Coughing up blood or mucus
- Weakness or fatigue
- Fever and chills
- Night sweats
If not treated properly, TB can be deadly. You can usually cure active TB by taking several medicines for a long period of time. People with latent TB can take medicine so that they do not develop active TB.
Centers for Disease Control and Prevention
27 Haziran 2011 Pazartesi
Right now there is no cure for HIV or AIDS, but new medicines can help people live longer lives. Scientists are also researching vaccines that may one day help to prevent HIV infection, but it's a very tough assignment, and no one knows when these vaccines might become available. It's up to everyone to prevent AIDS by avoiding the behaviors that lead to HIV infection.
Can HIV and AIDS Be Prevented?
People can help stop the spread of HIV by avoiding sexual contact with infected people and by not sharing needles or syringes.
Health care workers (such as doctors, nurses, and dentists) help prevent the spread of HIV by wearing plastic gloves when working on a patient. Hospitals have strict procedures for handling samples of blood and other body fluids to prevent others from coming in contact with HIV.
Living With HIV and AIDS
New drugs make it possible for people who are HIV positive to live for years without getting AIDS. They can work or go to school, make friends, hang out, and do most of the things other people can do. They will have to take certain medicines every day and see their doctors pretty often, and they may get sick more than other people do because their immune systems are more fragile.
Even though they may look OK, people who are HIV positive may sometimes feel scared, angry, unhappy, or depressed. They may feel afraid that the people at work or school could find out and start treating them differently. It is important for all of us to remember that usual social contact, like eating lunch or playing games, with people who are HIV positive does not bring any risk of infection.
When HIV infection gets worse or turns into the disease called AIDS, life really changes. The person may need to spend a lot of time in bed or in the hospital because of serious illnesses. He or she may feel very tired or weak most of the time. The person also might lose weight.
Hope for an HIV-Free Future
Maybe one day, with time and research, a cure for HIV infection will be found and AIDS will no longer exist. Until then, the smartest thing to do is to know the facts and not put yourself at risk.
If you have more questions about HIV or AIDS, talk to an adult you trust — a parent, doctor, school nurse, or guidance counselor. Don't depend only on your friends for information about HIV and AIDS because they may not know all the right answers.
Most people don't feel any different after they are infected with HIV. In fact, infected people often do not experience symptoms for years. Some people develop flu-like symptoms a few days to a few weeks after being infected, but these symptoms usually go away after several days.
An HIV-positive person will eventually begin to feel sick. The person might begin to have swollen lymph nodes, weight loss, fevers that come and go, infections in the mouth, diarrhea, or he or she might feel tired for no reason all of the time. Eventually, the virus can infect all of the body's organs, including the brain, making it hard for the person to think and remember things.
When a person's T cell count gets very low, the immune system is so weak that many different diseases and infections by other germs can develop. These can be life threatening. For example, people with AIDS often develop pneumonia (say: nu-mo-nyah), which causes bad coughing and breathing problems. Other infections can affect the eyes, the organs of the digestive system, the kidneys, the lungs, and the brain. Some people develop rare kinds of cancers of the skin or immune system.
Most of the children who have HIV got it because their mothers were infected and passed the virus to them before they were born. Babies born with HIV infection may not show any symptoms at first, but the progression of AIDS is often faster in babies than in adults. Doctors need to watch them closely. Kids who have HIV or AIDS learn more slowly than healthy kids and tend to start walking and talking later.
How Are HIV and AIDS Diagnosed?
A person can be infected with HIV without even knowing it. So doctors recommend that anyone who thinks he or she may have been exposed to the virus get tested — even if the chance of having been infected seems small. Doctors test a person's blood to find out if he or she is infected with HIV.
People who are HIV positive need to have more blood tests every so often. The doctor will want to check on how many T cells the person has. The lower the T cell count, the weaker the immune system and the greater the risk that someone will get very sick.
Since the discovery of the virus more than 20 years ago, millions of people throughout the world have been infected with HIV. Most are adults, but there are kids and teens who have HIV, too. In the world today, AIDS remains an epidemic (say: eh-puh-deh-mik), which means that it affects a large number of people and continues to spread rapidly.
Right now, about 40 million people in the world are living with HIV infection or AIDS. This estimate includes 37 million adults and 2.5 million children. In the United States alone, more than 1 million people are living with HIV.
How Is HIV Spread?
HIV infection isn't like a cold or the flu. A person cannot get HIV by hugging or holding the hand of, sharing a school bus or classroom with, or visiting the home of someone who has HIV. HIV is passed only through direct contact with another person's body fluids, such as blood. The majority of people in North America get infected with HIV by:
having sexual contact with a person who has HIV
sharing needles or syringes (used to inject illegal drugs) with a person who has HIV
Other ways of getting HIV can occur when:
an infected pregnant woman passes it to her unborn child (which can be prevented by treating the mother and child around the time the baby is delivered). Because of the risk to an untreated baby, every pregnant woman should be tested for HIV.
a person has a blood transfusion (say: trans-fyoo-zhun) from a fairly large volume of blood. But in North America today, all donated blood is tested for HIV, so the risk of getting HIV is less than 1 in a million.
People who are HIV positive have been tested and found to have signs of the human immunodeficiency virus in their blood. HIV destroys part of the immune (say: ih-myoon) system. Specifically, it affects a type of white blood cell called the T lymphocyte (say: lim-fuh-site), or T cell. T cells are one type of "fighter" cell in the blood that help the body fight off all kinds of germs and diseases.
After HIV enters the body, it piggybacks onto a T cell and works its way inside of that cell. Once inside, the virus completely takes over the T cell and uses it as a virus-making factory to make a lot of copies of itself. The newly made viruses then leave the T cell and go on to infect and destroy other healthy T cells as they continue to multiply inside the body. After the virus invades the T cells, they can no longer properly fight infections.
Someone who is infected with the virus is called HIV positive. But it may take years for the virus to damage enough T cells for that person to get sick and develop AIDS. And thanks to new medications, someone infected with HIV can stay relatively healthy and symptom-free for many years. But these medications are very expensive and not available to everyone in the world.
Although the HIV-positive person may feel fine, the virus is silently reproducing itself and destroying T cells. And during this time, the person is still contagious (say: kon-tay-jus), which means he or she is able to give the disease to others.
When the person's immune system has weakened and more of the blood's T cells have been destroyed by the virus, the person can no longer fight off infections. This is when he or she gets very sick. A doctor diagnoses a person with AIDS when the person has a very low number of T cells and shows signs of a serious infection.