The human immunodeficiency virus (HIV) weakens the immune system by destroying specific cells that help the body fight infection. People living with HIV may have no symptoms or a range of symptoms depending on how long they have had the infection.
HIV is a retrovirus that spreads from person to person through the exchange of specific body fluids. It enters the body through direct contact with mucous membranes or blood.
The symptoms of HIV can range from mild to severe, depending on the progress of the infection. Some people may have no symptoms or flu-like illness in the early stages.
Although there’s no cure for HIV, effective treatments with antiretroviral therapy (ART) are available. The outlook is good for those who begin appropriate and early ART.
Though there is no cure for HIV, effective treatments are available. Left untreated, HIV can lead to a life-threatening condition known as acquired immunodeficiency syndrome or AIDS.
What is HIV?
Human immunodeficiency virus, or HIV, is a retrovirus that harms the body’s immune system. A retrovirus is a virus that changes its RNA into DNA and then inserts its viral DNA into the genes of the cells it infects, allowing it to copy itself. Specifically, HIV infects CD4 cells, a type of white blood cell that helps the body fight infection from bacteria, viruses, and other germs.
After entering the body, HIV enters CD4 cells and adds its viral DNA to the DNA of the CD4 cell so it can continually copy itself. The new copies of HIV break out of the infected cells, attack other CD4 cells, and repeat the cycle. During this process, HIV destroys the CD4 cells.
If left untreated, the body eventually loses so many CD4 cells that it can no longer fight off infections, making people more vulnerable to life-threatening illnesses. This severe damage to the immune system is known as acquired immunodeficiency syndrome or AIDS.
So, while HIV can cause AIDS, most people with HIV infection don’t develop it.
How common is HIV?
Globally, HIV is a significant public health problem affecting people of all ages and genders. At the end of 2021, approximately 38.4 million people were living with HIV worldwide, including 1.7 million children under 15 years old. And although HIV remains a leading cause of death across the globe, about one in six people with HIV don’t know they’re infected.
How does HIV spread?
HIV is found in certain body fluids, including blood, vaginal fluids, semen, rectal fluids, and breast milk. The virus can spread from a person with HIV when these body fluids directly contact another person’s mucous membranes or blood. Mucous membranes are moist surfaces of the body and cover the inside of the vagina, penis, rectum, and mouth.
However, HIV is a fragile virus that cannot survive long outside the body. So, it can only spread through specific activities involving the direct exchange of body fluids. These include:
- Through unprotected vaginal or anal sex.
- By sharing needles or other injection drug use equipment.
- From mother to baby during pregnancy, childbirth, or breastfeeding.
In extremely rare cases, HIV can spread in other ways, including through:
- Oral sex.
- Transfusion of blood or blood products.
- Accidental needle pricks among healthcare workers.
HIV does not spread through casual contact such as hugging, kissing, sharing dishes, shaking hands, or living with someone who has HIV. It also cannot spread through the air, water, insect bites, or contact with objects such as doorknobs or toilet seats. Other body fluids such as saliva, tears, sweat, urine, or feces that don’t contain blood cannot pass HIV to another person.
What are the symptoms of HIV?
The symptoms of HIV infection vary. Some people have no initial symptoms, while about 50-90% of people experience flu-like symptoms within 2 to 4 weeks after infection. This phase is called acute HIV infection and can last a few days or weeks. It's symptoms can include:
- Sore throat.
- Muscle and joint aches.
- Swollen lymph nodes.
- Sores in the mouth, anus, or genitals.
- Nausea and vomiting.
- Weight loss.
- Loss of appetite.
- Dry cough.
During this early phase, a person is very contagious and can easily spread the virus to others even if they have no symptoms. If people don’t get treatment after these early symptoms disappear, the virus continues to make copies of itself and damage the immune system. This phase is called chronic HIV infection. During this phase, people often don’t feel sick or experience symptoms for ten years or more but can still pass on the virus to others.
Without treatment, HIV eventually progresses to AIDS, the last stage of infection. HIV severely damages the immune system during this phase, leading to more serious infections and other diseases. The symptoms of AIDS depend on the illness or illnesses that develop and may include mouth infections, lung infections, certain cancers, and neurological complications.
Outlook for people living with HIV
With proper treatment, HIV infection is a manageable, lifelong illness. Although there is no cure, people who begin treatment with antiretroviral therapy (ART) as soon as possible can live long lives and thrive like people with most other chronic health conditions.
However, good outcomes depend on the following:
- Taking all medications exactly as prescribed.
- Making healthy lifestyle choices.
- Having regular medical checkups.
HIV may cause no symptoms or flu-like symptoms during early infection. Left untreated, some people may continue to have no symptoms for ten years or longer before progressing to the most severe stage of infection known as AIDS. A person can pass HIV to others at any stage, even if they have no symptoms. And with or without symptoms, people with HIV can expect to live a long, healthy life if they receive the proper treatment and care as early as possible.
If you think you may have had direct contact with the body fluids of someone who has HIV, let your healthcare provider know so they can test and begin treatment if necessary.