The Effects of HIV on the Body

Most people are likely familiar with HIV, but they may not know how it can affect the body. HIV destroys CD4 cells (also called T cells or helper cells), which are critical to the immune system. CD4 cells are responsible for keeping people healthy and protecting them from common diseases and infections. As HIV gradually weakens the body’s natural defenses, signs and symptoms will occur.

Find out what happens when the virus enters the body and interrupts its systems.

Once HIV enters the body, it launches a direct attack on the immune system.

How quickly the virus progresses will vary by:

  • a person’s age
  • their overall health
  • how quickly they’re diagnosed
  • The timing of their treatment can make a huge difference as well.

HIV targets the types of cells that would normally fight off an invader such as HIV. As the virus replicates, it damages or destroys the infected CD4 cell and produces more virus to infect more CD4 cells.

Without treatment, this cycle can continue until the immune system is badly compromised, leaving a person at risk for serious illnesses and infections.

Acquired immunodeficiency syndrome (AIDS) is the final stage of HIV. At this stage, the immune system is severely weakened, and the risk of contracting opportunistic infections is much greater. However, not everyone with HIV will go on to develop AIDS. The earlier a person receives treatment, the better their outcome will be.

Immune system

The immune system prevents the body from acquiring the diseases and infections that come its way. White blood cells defend the body against viruses, bacteria, and other organisms that can make a person sick.

Early on, HIV symptoms may be mild enough to be dismissed

After a few days after being exposed to the virus, a person with HIV may experience a flu-like sickness that lasts a few weeks. This is associated with the first stage of HIV, which is called the acute infection stage, or acute HIV.

Acute infection

An HIV-positive person may not have many serious symptoms during this stage, but there are usually large quantities of virus in their blood as the virus reproduces rapidly.

Acute symptoms can include:

  • fever
  • chills
  • night sweats
  • diarrhea
  • headache
  • muscle aches
  • joint pain
  • sore throat
  • rash
  • swollen lymph nodes
  • mouth or genital ulcers

Chronic HIV infection

The next stage is called the chronic infection stage. It can last for as long as 10 to 15 years. An HIV-positive person may or may not show signs or have symptoms during this stage. As the virus advances, the CD4 count decreases more drastically. 

This can lead to symptoms such as:

  • fatigue
  • shortness of breath
  • cough
  • fever
  • swollen lymph nodes
  • weight loss
  • diarrhea
  • rash


If untreated HIV advances to AIDS, the body becomes prone to opportunistic infections.

AIDS increases a person’s risk for many infections, including a herpes virus called cytomegalovirus (CMV). It can cause problems with the eyes, lungs, and digestive tract.

Kaposi sarcoma, another possible complication, is a cancer of the blood vessel walls. It’s rare among the general population, but it’s more common in people with advanced HIV.

Symptoms include red or dark purple lesions on the mouth and skin. It can also cause problems in the lungs, the digestive tract, and other internal organs.

HIV and AIDS also put a person at higher risk for developing lymphomas. An early sign of lymphoma is swollen lymph nodes.

Respiratory and cardiovascular systems

HIV makes it hard to fight off respiratory problems such as the common cold and flu. In turn, an HIV-positive person may develop related infections, such as pneumonia. Without treatment for HIV, advanced disease puts an HIV-positive person at an even greater risk for infectious complications, such as tuberculosis and a fungal infection called pneumocystis jiroveci pneumonia (PJP).

PJP causes trouble breathing, cough, and fever.

The risk of lung cancer also increases with HIV. This is due to weakened lungs from numerous respiratory issues related to a weakened immune system.

According to available researchTrusted Source, lung cancer is more prevalent among people with HIV compared to people without it. People with HIV are more likely to develop high blood pressure. HIV also raises the risk of pulmonary arterial hypertension (PAH). PAH is a type of high blood pressure in the arteries that supply blood to the lungs. Over time, PAH will strain the heart and can lead to heart failure.

If a person has HIV with a low CD4 count, they’re also more susceptible to tuberculosis (TB). TB is an airborne bacterium that affects the lungs. It’s a leading cause of death in people who have AIDS. Symptoms include chest pain and a bad cough that may contain blood or phlegm. The cough can linger for months.


Healthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

About HIV. (2021).

Neurological complications of HIV and AIDS fact sheet. (2020).

Oakley A. (2003). Skin conditions relating to HIV infection.

Pneumocystis pneumonia. (2020).

Sigel K, et al. (2016). Lung malignancies in HIV infection.

Symptoms of HIV. (2020).

TB causes 1 in 3 HIV deaths. (2018).

Tuberculosis: Signs & symptoms. (2016).

What are HIV and AIDS? (2020).


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