At which stage of HIV infection a person usually shows symptoms of AIDS ?

When HIV damages and decrease the number of T-lymphocytes.

The stage at which a person usually begins to show symptoms of AIDS (Acquired Immunodeficiency Syndrome) is when HIV damages and decreases the number of T-lymphocytes, specifically when the immune system becomes significantly compromised.

HIV (Human Immunodeficiency Virus) attacks and destroys CD4 T-lymphocytes (a type of white blood cell), which are vital for the proper functioning of the immune system. As the virus replicates and gradually reduces the number of these immune cells, the body becomes increasingly susceptible to various infections and diseases. When the number of T-lymphocytes declines significantly, and the immune system becomes severely weakened, symptoms of AIDS start to appear, and the person becomes more susceptible to opportunistic infections and certain types of cancers.

There is always a time-lag between the infection and appearance of AIDS symptoms. This period may vary from a few months to many years (usually 5-10 years).HIV enters into helper T-lymphocytes (TH ), replicates and produce progeny viruses. The progeny viruses released in the blood attack other helper T-lymphocytes. This is repeated leading to a progressive decrease in the number of helper T-lymphocytes in the body of the infected person. During this period, the person suffers from bouts of fever, diarrhoea and weight loss.