Acquired immunodeficiency syndrome (AIDS) is a chronic, potentially life-threatening condition caused by the human immunodeficiency virus (HIV). By damaging your immune system, HIV interferes with your body's ability to fight the organisms that cause disease.
HIV is a sexually transmitted infection. It can also be spread by contact with infected blood or from mother to child during pregnancy, childbirth or breast-feeding. Without medication, it may take years before HIV weakens your immune system to the point that you have AIDS.
There's no cure for HIV/AIDS, but there are medications that can dramatically slow the progression of the disease. These drugs have reduced AIDS deaths in many developed nations. But HIV continues to decimate populations in Africa, Haiti and parts of Asia.
The symptoms of HIV and AIDS vary, depending on the phase of infection.
Primary infection (Acute HIV)
The majority of people infected by HIV develop a flu-like illness within a month or two after the virus enters the body. This illness, known as primary or acute HIV infection, may last for a few weeks. Possible signs and symptoms include:
- Muscle aches and joint pain
- Sore throat
- Swollen lymph glands, mainly on the neck
Although the symptoms of primary HIV infection may be mild enough to go unnoticed, the amount of virus in the bloodstream (viral load) is particularly high at this time. As a result, HIV infection spreads more efficiently during primary infection than during the next stage of infection.
Clinical latent infection (Chronic HIV)
In some people, persistent swelling of lymph nodes occurs during clinical latent HIV. Otherwise, there are no specific signs and symptoms. HIV remains in the body, however, and in infected white blood cells.
Clinical latent infection generally lasts around 10 years if you're not receiving antiretroviral therapy. This phase can last for decades in people taking antiretroviral medications. But some people progress to more severe disease much sooner.
Early symptomatic HIV infection
As the virus continues to multiply and destroy immune cells, you may develop mild infections or chronic signs and symptoms such as:
- Swollen lymph nodes — often one of the first signs of HIV infection
- Weight loss
- Oral yeast infection (thrush)
- Shingles (herpes zoster)
Progression to AIDS
If you receive no treatment for your HIV infection, the disease typically progresses to AIDS in about 10 years. By the time AIDS develops, your immune system has been severely damaged, making you susceptible to opportunistic infections — diseases that wouldn't usually trouble a person with a healthy immune system.
The signs and symptoms of some of these infections may include:
- Soaking night sweats
- Recurring fever
- Chronic diarrhea
- Persistent white spots or unusual lesions on your tongue or in your mouth
- Persistent, unexplained fatigue
- Weight loss
- Skin rashes or bumps
When to see a doctor
If you think you may have been infected with HIV or are at risk of contracting the virus, see a health care provider as soon as possible.
HIV is a viral infection that can be transmitted through sexual contact, through blood or from mother to child during pregnancy, childbirth or breast-feeding.
How does HIV become AIDS?
HIV destroys CD4 cells — a specific type of white blood cell that plays a large role in helping your body fight disease. Your immune system weakens as more CD4 cells are killed. You can have an HIV infection for years before it progresses to AIDS.
People infected with HIV progress to AIDS when their CD4 count falls below 200 or they experience an AIDS-defining complication.
How HIV is transmitted
To become infected with HIV, infected blood, semen or vaginal secretions must enter your body. You can't become infected through ordinary contact — hugging, kissing, dancing or shaking hands — with someone who has HIV or AIDS. HIV can't be transmitted through the air, water or insect bites.
You can become infected with HIV in several ways, including:
- By having sex. You may become infected if you have vaginal, anal or oral sex with an infected partner whose blood, semen or vaginal secretions enter your body. The virus can enter your body through mouth sores or small tears that sometimes develop in the rectum or vagina during sexual activity.
- From blood transfusions. In some cases, the virus may be transmitted through blood transfusions. American hospitals and blood banks now screen the blood supply for HIV antibodies, so this risk is very small.
- By sharing needles. HIV can be transmitted through needles and syringes contaminated with infected blood. Sharing intravenous drug paraphernalia puts you at high risk of HIV and other infectious diseases, such as hepatitis.
- During pregnancy or delivery or through breast-feeding. Infected mothers can infect their babies. But by receiving treatment for HIV infection during pregnancy, mothers significantly lower the risk to their babies.
When HIV/AIDS first surfaced in the United States, it mainly affected men who had sex with men. However, now it's clear that HIV is also spread through heterosexual sex.
Anyone of any age, race, sex or sexual orientation can be infected, but you're at greatest risk of HIV/AIDS if you:
- Have unprotected sex. Unprotected sex means having sex without using a new latex or polyurethane condom every time. Anal sex is more risky than is vaginal sex. The risk increases if you have multiple sexual partners.
- Have another STI. Many sexually transmitted infections (STIs) produce open sores on your genitals. These sores act as doorways for HIV to enter your body.
- Use intravenous drugs. People who use intravenous drugs often share needles and syringes. This exposes them to droplets of other people's blood.
- Are an uncircumcised man. Studies indicate that lack of circumcision increases the risk of heterosexual transmission of HIV.
HIV infection weakens your immune system, making you highly susceptible to numerous infections and certain types of cancers.
Infections common to HIV/AIDS
- Tuberculosis (TB). In resource-poor nations, TB is the most common opportunistic infection associated with HIV and a leading cause of death among people with AIDS.
- Cytomegalovirus. This common herpes virus is transmitted in body fluids such as saliva, blood, urine, semen and breast milk. A healthy immune system inactivates the virus, and it remains dormant in your body. If your immune system weakens, the virus resurfaces — causing damage to your eyes, digestive tract, lungs or other organs.
- Candidiasis. Candidiasis is a common HIV-related infection. It causes inflammation and a thick, white coating on the mucous membranes of your mouth, tongue, esophagus or vagina.
- Cryptococcal meningitis. Meningitis is an inflammation of the membranes and fluid surrounding your brain and spinal cord (meninges). Cryptococcal meningitis is a common central nervous system infection associated with HIV, caused by a fungus found in soil.
- Toxoplasmosis. This potentially deadly infection is caused by Toxoplasma gondii, a parasite spread primarily by cats. Infected cats pass the parasites in their stools, and the parasites may then spread to other animals and humans.
- Cryptosporidiosis. This infection is caused by an intestinal parasite that's commonly found in animals. You contract cryptosporidiosis when you ingest contaminated food or water. The parasite grows in your intestines and bile ducts, leading to severe, chronic diarrhea in people with AIDS.
Cancers common to HIV/AIDS
Kaposi's sarcoma. A tumor of the blood vessel walls, this cancer is rare in people not infected with HIV, but common in HIV-positive people.
Kaposi's sarcoma usually appears as pink, red or purple lesions on the skin and mouth. In people with darker skin, the lesions may look dark brown or black. Kaposi's sarcoma can also affect the internal organs, including the digestive tract and lungs.
- Lymphomas. This type of cancer originates in your white blood cells and usually first appears in your lymph nodes. The most common early sign is painless swelling of the lymph nodes in your neck, armpit or groin.
- Wasting syndrome. Aggressive treatment regimens have reduced the number of cases of wasting syndrome, but it still affects many people with AIDS. It's defined as a loss of at least 10 percent of body weight, often accompanied by diarrhea, chronic weakness and fever.
- Neurological complications. Although AIDS doesn't appear to infect the nerve cells, it can cause neurological symptoms such as confusion, forgetfulness, depression, anxiety and difficulty walking. One of the most common neurological complications is AIDS dementia complex, which leads to behavioral changes and diminished mental functioning.
Kidney disease. HIV-associated nephropathy (HIVAN) is an inflammation of the tiny filters in your kidneys that remove excess fluid and wastes from your bloodstream and pass them to your urine. Because of a genetic predisposition, the risk of developing HIVAN is much higher in blacks.
Regardless of CD4 count, antiretroviral therapy should be started in those diagnosed with HIVAN.
There's no vaccine to prevent HIV infection and no cure for AIDS. But it's possible to protect yourself and others from infection. That means educating yourself about HIV and avoiding any behavior that allows HIV-infected fluids — blood, semen, vaginal secretions and breast milk — into your body.
To help prevent the spread of HIV:
Use a new condom every time you have sex. If you don't know the HIV status of your partner, use a new condom every time you have anal or vaginal sex. Women can use a female condom.
Use only water-based lubricants. Oil-based lubricants can weaken condoms and cause them to break. During oral sex use a nonlubricated, cut-open condom or a dental dam — a piece of medical-grade latex.
Consider the drug Truvada. Use of the combination drug emtricitabine-tenofovir (Truvada) can reduce the risk of sexually transmitted HIV infection in those who are at high risk. Truvada is also used as an HIV treatment along with other medications.
When used to help prevent HIV infection, Truvada is only appropriate if your doctor is certain you don't already have an HIV infection. Your doctor should also test for hepatitis B infection. If you have hepatitis B, your doctor should test your kidney function before prescribing Truvada.
Truvada must be taken daily, exactly as prescribed. Truvada should only be used along with other prevention strategies, such as condom use every time you have sex, as it doesn't protect against other sexually transmitted infections, and it can't provide complete protection against HIV transmission. If you're interested in Truvada, talk with your doctor about the potential risks and benefits of the drug.
- Tell your sexual partners if you have HIV. It's important to tell anyone with whom you've had sex that you're HIV-positive. Your partners need to be tested and to receive medical care if they have the virus. They also need to know their HIV status so that they don't infect others.
- Use a clean needle. If you use a needle to inject drugs, make sure it's sterile and don't share it. Take advantage of needle-exchange programs in your community and consider seeking help for your drug use.
- If you're pregnant, get medical care right away. If you're HIV-positive, you may pass the infection to your baby. But if you receive treatment during pregnancy, you can cut your baby's risk significantly.
- Consider male circumcision. There's evidence that male circumcision can help reduce a man's risk of acquiring HIV.