Once the human immunodeficiency virus (HIV) enters your body, it launches a direct attack on your immune system. How quickly the virus progresses will vary by your age, overall health, and how quickly you’re diagnosed. The timing of your treatment can make a huge difference.

HIV targets the type of cells that would normally fight off an invader like 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 your immune system is badly compromised, leaving you 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 you receive treatment, the better your outcome will be.

Many of the effects described here are related to the failure of the immune system in HIV and AIDS that is progressing. Many of these effects are preventable with early antiretroviral treatment, which can preserve the immune system.

Immune system

Your immune system prevents your body from acquiring the diseases and infections that come your way. White blood cells defend you against viruses, bacteria, and other organisms that can make you sick.

Early on, symptoms may be mild enough to be dismissed, but after a few months, you may experience a flu-like sickness that lasts a few weeks. This is often associated with the first stage of HIV, which is called the acute infection stage. You may not have many serious symptoms, but there are usually large quantities of virus in your blood as the virus reproduces rapidly.

Acute symptoms can include:

The next stage is called the clinical latent infection state. On average, it lasts 8 to 10 years. In some cases, it lasts much longer than that. You may or may not show signs or have symptoms during this stage.

As the virus advances, your CD4+ count decreases more drastically. This can lead to symptoms such as:

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

If the HIV infection advances to AIDS, the body becomes prone to opportunistic infections. This puts you at an increased risk of many infections, including a herpes virus called cytomegalovirus. It can cause problems with your eyes, lungs, and digestive tract.

Kaposi sarcoma, another possible infection, is a cancer of the blood vessel walls. It’s rare among the general population, but common in people who are HIV-positive. Symptoms include red or dark purple lesions on the mouth and skin. It can also cause problems in the lungs, digestive tract, and other internal organs.

HIV and AIDS also puts you at higher risk of developing lymphomas. An early sign of lymphoma is swollen lymph nodes.

Respiratory and cardiovascular systems

HIV increases the risk of colds, influenza, and pneumonia. Without preventive treatment for HIV, advanced treatment puts you at an even greater risk for complications like tuberculosis, pneumonia, and a disease called pneumocystis carinii pneumonia (PCP). PCP causes:

  • trouble breathing
  • cough
  • fever

Your risk for lung cancer also increases with HIV. This is caused by weakened lungs from numerous respiratory issues related to a weakened immune system. According to National AIDS Manual (NAM), lung cancer is more prevalent among people with HIV compared to people without it.

HIV 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 your heart.

If you have HIV and have become immunocompromised (have a low T cell count), you’re also more susceptible to tuberculosis (TB), a leading cause of death in people who have AIDS. TB is an airborne bacterium that affects the lungs. Symptoms include chest pain and a bad cough that may contain blood or phlegm, which can linger for months.

Digestive system

Since HIV affects your immune system, it also makes your body more susceptible to infections that can affect your digestive system. Problems with your digestive tract can also decrease your appetite and make it difficult to eat properly. As a result, weight loss is a common side effect.

A common infection related to HIV is oral thrush, which includes inflammation and a white film on the tongue. It can also cause inflammation of the esophagus, which can make it difficult to eat. Another viral infection that affects the mouth is oral hairy leukoplakia, which causes white lesions on the tongue.

Salmonella infection is spread through contaminated food or water, and causes diarrhea, abdominal pain, and vomiting. Anyone can get it, but if you have HIV, you’re at higher risk of serious complications from this infection.

Consuming contaminated food or water can also result in a parasitic intestinal infection called cryptosporidiosis. This infection affects the bile ducts and intestines and can be particularly severe. For people with AIDS, it can cause chronic diarrhea.

HIV-associated nephropathy (HIVAN) is when the filters in your kidneys become inflamed, making it harder to remove waste products from your bloodstream.

Central nervous system

While HIV doesn’t generally directly infect nerve cells, it does infect the cells that support and surround nerves in the brain and throughout the body.

While the link between HIV and neurologic damage isn’t completely understood, it’s likely that infected support cells contribute to nerve injury. Advanced HIV infection can damage nerves (neuropathy). Small holes in the conducting sheaths of peripheral nerve fibers (vacuolar myelopathy) can cause pain, weakness, and difficulty walking.

There are significant neurological complications of AIDS. HIV and AIDS can cause HIV- associated dementia or AIDS dementia complex, two conditions that seriously affect cognitive function.

Toxoplasma encephalitis, caused by a parasite commonly found in cat feces, is another possible complication of AIDS. With a weakened immune system, having AIDS puts you at an increased risk of inflammation of the brain and spinal cord due to this parasite. Symptoms include confusion, headaches, and seizures.

Some common complications of AIDS include:

  • memory impairment
  • anxiety
  • depression

In very advanced cases, hallucinations and frank psychosis can occur. You may also experience headaches, balance issues, and vision problems.

Integumentary system

One of the more visible signs of HIV and AIDS can be seen on the skin. A weakened immune response leaves you more vulnerable to viruses like herpes. Herpes can cause you to develop sores around your mouth or genitals.

HIV also increases your risk for rashes and shingles. Shingles are caused by herpes zoster, the virus that gives you chickenpox. Shingles causes a painful rash, often with blisters.

A viral skin infection called molluscum contagiosum involves an outbreak of bumps on the skin. Another condition is called prurigo nodularis. It causes crusted lumps on the skin, as well as severe itching.

HIV can also make you prone to other skin conditions, such as: