by Alan R
(Human Immunodeficiency Virus and Acquired Immunodeficiency Syndrome)


Human immunodeficiency virus (HIV) is a virus that attacks a part of the immune system. It targets white blood cells called CD4 (T cells). They are needed to fight off infections and other diseases. Low levels of CD4 cells make it harder for the body to stop or control infections and diseases.

AIDS is a late stage of HIV infection. It is a sign of severe damage to the immune system. This level of damage can lead to infections that do not usually occur in healthy people. It also allows the growth of some cancers.

Immune System
Immune system white blood cell
HIV destroys white blood cells vital to the immune system.
Copyright © Nucleus Medical Media, Inc.


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
  • HIV-contaminated needle

Rarely, HIV can be spread through:

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

Risk Factors

Factors that may increase your chance of HIV infection include:

  • Sex with a high-risk individual or individual already infected with HIV
  • Multiple sexual partners
  • Sex without using a condom including vaginal and anal sex
  • Having other sexually transmitted diseases
  • 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 is unlikely due to strict screening processes)
  • Uncircumcised penis—circumcised men are less likely to develop HIV infection than uncircumcised men


HIV may not cause problems for a number of years.

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

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

There may be no additional symptoms for months to years. Symptoms that do occur over the years may include:

  • Lack of appetite
  • Fatigue
  • Muscle wasting
  • Swollen lymph glands all over the body
  • Memory loss
  • Development of lots of warts
  • Fungal infections of the mouth, fingernails, toes
  • Repeated vaginal infections
  • Flare-ups of prior conditions, such as eczema, psoriasis, or herpes
  • Chronic diarrhea

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:


Your doctor will ask about your symptoms and medical history. A physical exam will be done. Tests to confirm a diagnosis of HIV infection include:

  • 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
  • Your doctor may also test for other infections. You may be tested for one or more of the following:
    • Tuberculosis
    • Hepatitis A, B, and C
    • Other sexually transmitted diseases (STDs)


There is no cure for HIV at this time. The goal of treatment is to control HIV. Treatment, called antiretroviral treatment (ART), can:

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

Medicines That Fight HIV

Antiviral medicine can stop the virus from multiplying and harming the immune system. However, it cannot get rid of the virus. Once treatment is stopped the virus will likely grow and spread again. Antiviral medicines are often given in combination. Categories of these medicines include:

  • 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 Opportunistic Infections

The doctor may recommend some steps to prevent new infections. This will depend on your CD4 count and other risk factors. Options may include:

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

Support and Counseling

Chronic diseases can impact your day to day life. There are many support options that may help with these challenges. Options include:

  • Support group
  • Local organizations
  • Counseling
  • Peer groups

Reducing risk of transmission

There are steps you can take to decrease the risk of spreading HIV to others:

  • Follow your ART care plan. Keeping an undetectable viral load will lower the chance of passing HIV to another person to zero.
  • If you have sex, use a latex condom every time. It will be needed during any sexual act with an exchange of body fluids. Other options to consider:
    • A female condom may be used. This type of condom has not been well studied. However, a female condom is better than nothing.
    • A dental dam can be used during oral sex. It is a small square of latex.
  • Let past, present, and future sexual partners know about the infection. Encourage them to get tested.
  • Do not donate blood.
  • If you are not planning a pregnancy, ask your doctor about contraception.
  • If you do wish to become pregnant, talk to your doctor. There are ways to lower your baby's risk of being born infected with HIV.
  • If you have a baby, do not breastfeed. HIV can pass through breastmilk.


AMFAR—The Foundation for AIDS Research 

Centers for Disease Control and Prevention 


AIDS Committee of Toronto 

Canadian AIDS Society 


Bailey RC, Moses S, Parker CB, et al. Male circumcision for HIV prevention in young men in Kisumu, Kenya: A randomised controlled trial. Lancet. 2007;369(9562):643-656.

Gray RH, Kigozi G, Serwadda D, et al. Male circumcision for HIV prevention in men in Rakai, Uganda: a randomised trial. Lancet. 2007;369(9562):657-666.

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Prevention of Opportunistic Infections in Patients With HIV. EBSCO DynaMed website. Available at: Accessed February 18, 2021.

Preventing transmission of HIV. AIDS info website. Available at: Accessed February 18, 2021.

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