The HIV virus weakens the immune system by disabling important immune cells (T helper cells). After HIV transmission, the virus penetrates the cells and causes them to produce further HI viruses and no longer fulfil their original function.

Without treatment, the body may stop being able to fight pathogens, such as bacteria, fungi and viruses, which a properly functioning immune system can deal with easily. Over time, this result in certain life-threatening illnesses such as severe pneumonia, fungal infections and Kaposi’s sarcoma. At this point, the virus has developed into Acquired Immune Deficiency Syndrome (AIDS). 

Today's HIV medications suppress the virus in the body until it is no longer detectable, thus preventing the onset of AIDS and allowing people with HIV to live for a long time and enjoy a good quality of life.

How does HIV progress?

If an HIV infection is not treated with medication, it generally goes through four stages. The duration of each stage is different for each person. As such, the amount of time people with untreated HIV can live without symptoms also differs from one person to the next. It can range from a few months to more than 15 years. The later an infection is diagnosed, the greater the potential for health problems.

Stage 1: Acute HIV infection (primary infection) 

The virus multiplies particularly quickly in the body during the period directly after an HIV infection. This makes HIV much easier to transmit to sexual partners during this stage. In the first two to four weeks after infection, it is common to experience symptoms similar to a cold or a mild flu. This is known as primary infection.

Stage 2: Asymptomatic stage (clinical latency stage) 

The symptoms from the first stage go away on their own after a few weeks as the immune system responds to the virus by producing antibodies. For some time after this, the HIV infection does not present any symptoms. Most people with HIV remain free of symptoms for years. However, if left untreated, the virus will continue to replicate, all the while putting strain on the immune system.

Stage 3: General symptoms stage

Prolonged exposure to untreated HIV weakens the immune system over time, rendering it incapable of responding adequately to pathogens. At this stage, the body shows more and more signs of immunodeficiency. These can include skin diseases such as shingles, swelling of the lymph nodes, heavy night sweats, persistent diarrhoea, fever, persistent fungal infections, and nerve damage on the arms and legs causing pain, tingling and numbness.

Stage 4: AIDS

During this stage, the immune system is so heavily compromised that it can longer prevent severe, life-threatening illnesses. When certain combinations of illnesses occur, this is known as AIDS. There is a wide range of these so-called AIDS-defining conditions, including cancer, certain types of pneumonia, and fungal infections of the oesophagus and the trachea. After the onset of AIDS, life expectancy without treatment ranges from a few months to three years.