HIV is spread through contact with HIV-infected body fluids. This includes blood, semen, vaginal fluid, and breast milk.

HIV is most commonly spread through:

  • Sexual contact (especially vaginal or anal sex) with an HIV-infected person who is not taking medicine or has not reached maximal suppression of the virus
  • Transfer of HIV from a mother to child during pregnancy, childbirth, or breastfeeding
  • An HIV-contaminated needle

Rarely, HIV can be spread through:

  • A transfusion of HIV-infected blood
  • Blood from an HIV-infected person getting into an open wound of another person
  • Being bitten by an HIV-infected person
  • Sharing personal hygiene items that have been contaminated with blood or other body fluids of an HIV-infected person

Risk Factors

Things that may raise the risk of an HIV infection are:

  • Sex with a high-risk person or a person who is already infected with HIV
  • Having more than one sex partner
  • Sex without using a condom, including vaginal and anal sex
  • Having other sexually transmitted infections (STIs)
  • Injecting drugs with used or dirty needles
  • Regular exposure to HIV-contaminated blood or other body fluids
  • Being born to an HIV-infected mother
  • Receiving donor blood products, tissue, organs, or artificial insemination before 1985 (infections from donated tissue after 1985 are unlikely due to screening methods)
  • Uncircumcised penis—circumcised men are less likely to develop HIV infection

People whose behaviors put them at risk for HIV should talk to their doctors. They can lower their risk by taking an antiviral called PrEP as prescribed.



HIV may not cause problems for a number of years.

Early symptoms may appear 1 to 2 months after an infection and may last a couple of weeks. They may include:

  • Fever
  • Joint and muscle aches
  • Night sweats
  • Fatigue
  • Swelling in the armpits, neck, or groin
  • Headache
  • Sore throat
  • Rash
  • Diarrhea

After this, a person may not have symptoms for months to years. Symptoms that do happen over the years may include:

  • Lack of appetite
  • Lack of energy
  • Muscle weakness
  • Swollen glands all over the body
  • Memory loss
  • Warts
  • Flare-ups of other health problems, such as eczema, psoriasis, or herpes

If left untreated, HIV infection may progress to AIDS. This may happen when the number of CD4 cells fall below certain levels. The body is more vulnerable to infections such as:

  • Thrush
  • Some types of pneumonia
  • Fungal infections in the brain and lungs
  • Toxoplasmosis
  • Tuberculosis
  • Viral brain infection
  • Kaposi sarcoma
  • Lymphoma
  • Cervical cancer
  • Eye disease due to cytomegalovirus infection
  • Intestinal infections
  • Muscle wasting syndrome
  • Severe skin rashes
  • Reactions to medicines
  • Mental health problems, such as depression and dementia


The doctor will ask about symptoms and health history. A physical exam will be done. Tests will be done to look for signs of infection, such as:

  • HIV antibody test—to detect specific proteins in blood or saliva
  • Plasma RNA, or viral load test—to detect the amount of HIV in the blood



There is no cure for HIV. The goal of treatment is to control HIV with antiretroviral treatment (ART). This can:

  • Keep the immune system at normal or near-normal levels
  • Prevent progression to AIDS
  • Lower the risk of passing the virus to someone else
  • Play an important role in treating HIV-related infections and cancers

Medicines That Fight HIV

Antiviral medicine can stop the virus from multiplying and harming the immune system. But it cannot get rid of the virus. Stopping treatment would result in the virus growing and spreading again. Antiviral medicines are often given in combination. Categories of these medicines are:

  • Nucleoside reverse transcriptase inhibitors
  • Nonnucleoside reverse transcriptase inhibitors
  • Protease inhibitors
  • HIV-1 integrase inhibitors
  • HIV-1 fusion inhibitors
  • CC chemokine receptor 5 antagonists

Medicine needs to be taken as directed for best results. The care team can help to address side effects or cost problems. Blood tests will be done on a regular schedule. They can show if treatment is working and look for possible side effects.

Preventing New Infections

The doctor may advise steps to prevent new infections. This will depend on a person's CD4 count and other risk factors. Options may be:

  • Vaccination
  • Medicine
  • Advice on foods or situations that may pose a risk

Support and Counseling

Chronic diseases can impact day to day life. There are many support options that can help. Options are:

  • Support groups
  • Local organizations
  • Counseling
  • Peer groups

Lowering the Risk of Spreading HIV

Steps will need to be taken to lower the risk of spreading HIV to others, such as:

  • Following an ART care plan to keep an undetectable viral load
  • Using a latex condom and dental dam during sexual activity
  • Letting past, present, and future sex partners know about the infection and encouraging them to get tested
  • Not donating blood
  • Talking to the doctor about contraception
  • Talking to the doctor before becoming pregnant
  • Not breastfeeding

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.