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Understanding HIV and AIDS

If you know how HIV (human immunodeficiency virus) can get into your body and what happens once it’s there, you’ll be better prepared to protect yourself or others against this virus. A person with HIV can look and feel perfectly healthy. But that person can give HIV to others as soon as he or she is infected with the virus.

Note: Having unsafe or unprotected sex or sharing needles put you at risk for HIV. Talk with your healthcare provider about ways to protect yourself or a loved one from getting HIV.

Cross section of fragile inner tissue next to break in tough outer skin. Arrows show semen, vaginal fluid, and blood entering skin through break and directly into inner tissue.

How HIV enters the body

HIV is carried in semen, vaginal fluid, blood, and breast milk.

  • During sex, HIV can enter the body through the fragile tissue that lines the vagina, penis, anus, and mouth.

  • During drug use, tattooing, or body piercing, the virus can enter the bloodstream through a shared needle.

  • A mother who has HIV can infect her child during childbirth and through breastfeeding.

How HIV infection progresses

After HIV enters the body, it attacks the immune system in stages. A person with HIV can infect others once the virus enters the bloodstream.

HIV with no symptoms. A person with HIV may have no symptoms for years. A positive blood test for HIV antibodies 6 weeks to 6 months after HIV enters the body may be the only sign of infection.

HIV with symptoms. Some people develop an illness similar to mononucleosis (or "mono") 2 to 4 weeks after the virus enters the body. Symptoms may include swollen lymph glands, chills, fever, night sweats, weakness, weight loss, skin rashes, mouth ulcers, or sore throat. Symptoms may be mild at first and then slowly go away. In a very few individuals, symptoms may get progressively worse and last for longer and longer periods.

AIDS. AIDS is the last stage of HIV infection. Diseases and cancers begin to overcome the body. It is these diseases, not the virus itself, that cause death. HIV may also attack the brain and nervous system, causing seizures and loss of memory and body movement.

Online Medical Reviewer: Lentnek, Arnold, MD
Online Medical Reviewer: Sather, Rita, RN
Date Last Reviewed: 11/1/2016
© 2000-2017 The StayWell Company, LLC. 800 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.