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Understanding HIV and AIDS

It's important to know how HIV can get into your body. And to know what happens once it’s there. Then you’ll be better prepared to protect yourself and others against this virus. A person with HIV can look and feel healthy. But they can give HIV to others as soon as they are infected with the virus.

How HIV enters the body

HIV is carried in semen, vaginal fluid, blood, and breastmilk.

  • During sex, HIV can enter the body. It gets in through tissue and linings, sores, or cuts in or around the vagina, penis, anus, and mouth.

  • During illegal drug use, tattooing, or body piercing, the virus can enter the blood through an infected needle.

  • A person who has HIV can infect their child during pregnancy, birth, or breastfeeding.

How HIV infection progresses

After HIV enters the body, it attacks the immune system in the stages below. A person with HIV can infect others once the virus gets into the blood. This can happen even when someone with HIV has no symptoms.

  • HIV with no symptoms. A person with HIV may have no symptoms for years. The only sign of infection may be a positive blood test for HIV, from 10 days up to 3 months after HIV enters the body.

  • HIV with symptoms. Some people develop an illness that's a lot like mono (mononucleosis). This occurs 2 to 4 weeks after the virus enters the body. This is called acute retroviral syndrome. Symptoms may include:

    • Swollen lymph glands

    • Chills

    • Fever

    • Night sweats

    • Weakness

    • Weight loss

    • Skin rashes

    • Mouth sores

    • Sore throat

    Symptoms may be mild. Or the person can feel quite sick. Even without treatment the symptoms almost always go away in a few days or up to 2 to 3 weeks. Then the person has no symptoms, often for years. But over time the immune system starts to get weaker and symptoms start appearing. People at this stage may have:

    • A yeast infection in the mouth (oral thrush)

    • Shingles

    • Skin problems

    • Pneumonia

    • Diarrhea that keeps coming back

    • Weight loss

  • AIDS (acquired immunodeficiency syndrome). If a person with HIV isn't treated, the infection can develop into AIDS. This is the most advanced stage of HIV infection. It is when the immune system is severely weakened. Some rare diseases and cancers that normally wouldn't occur, now can occur. This is because the body can no longer fight them well enough. It's often these diseases that cause death in people with AIDS. HIV may also directly attack the brain and nervous system. This causes seizures and memory loss. It affects body movement. It also affects many other parts of the body. This leads to many problems such as:

    • Anemia

    • Low white blood cell count

    • Belly pain

    • Skin problems

    • Other problems

Online Medical Reviewer: Rita Sather RN
Online Medical Reviewer: Sabrina Felson MD
Online Medical Reviewer: Shaziya Allarakha MD
Date Last Reviewed: 3/1/2024
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