Human Immunodeficiency Virus (HIV)

HIV infection is caused by the human immunodeficiency virus. People can get HIV when they come in contact with infected blood, semen, or vaginal fluids. This is usually through sexual contact or sharing needles. If you have HIV while you're pregnant, the virus can be passed to your baby during birth.

HIV may not cause symptoms early on. People who do have symptoms may mistake them for the flu or mono. The symptoms may include:

• Fatigue.
• Muscle aches.
• Skin rash.
• Headache.
• Sore throat.
• Enlarged lymph nodes in the neck, armpits, and groin.
• Joint pain.
• Night sweats.
• Diarrhea.

These first symptoms can range from mild to severe. They usually go away on their own after two to three weeks. But many people don't have symptoms, or they have such mild symptoms that they don't notice them at this stage.

Later symptoms

After the early symptoms go away, a person who has HIV may not have symptoms again for years. But if HIV isn't treated, symptoms will come back, be more severe, and remain. These symptoms usually include:

• Extreme fatigue.
• Night sweats.
• Loss of appetite or unexplained weight loss.
• Swollen lymph nodes in the neck, armpits, and groin.
• Diarrhea or other bowel changes.
• Dry cough or shortness of breath.
• Nail changes.
• Pain when swallowing.
• Repeated outbreaks of cold sores or genital herpes sores.
• Mouth sores or a yeast infection of the mouth (thrush).

HIV is usually diagnosed with a blood test. Some tests use saliva or urine.

An HIV test checks for HIV antibodies or antigens. If HIV antibodies or antigens are found, the test is considered positive. If the test is positive, another test, such as a polymerase chain reaction (PCR) test, may be done to be sure. Sometimes a PCR test is done at the same time as the first test.

Even if HIV antibodies or antigens aren't found, you may need to be tested again, especially if you think you have been recently exposed. This is done to make sure that HIV antibodies or antigens don't appear at a later time.

HIV is treated with a mix of medicines called antiretroviral therapy (ART). Often the medicines are combined into a single pill. ART slows the rate at which the virus grows and can reduce the amount of virus in your body. Taking the medicine can prevent AIDS and help you stay healthy.

Experts suggest that people start treatment for HIV as soon as they know that they're infected.

It's important to take your medicines exactly as directed. When treatment doesn't work, it's often because the virus has become resistant to the medicine. This can happen if you miss doses.