Acquired immunodeficiency virus, or AIDS, is the end process of the human immunodeficiency virus, or HIV. A person who has AIDS must have HIV, whereas someone with HIV may not yet have AIDS. HIV and AIDS are immune system diseases; by the time AIDS develops the immune system is so damaged that it cannot ward off even simple infections.
Subjective Symptoms
Prior to developing AIDS, most people who suffer HIV are asymptomatic, or without symptoms. The physical symptoms of AIDS will vary dependent upon the stage of the disease. An incurable disease, these symptoms will worsen until death is imminent. Physical signs include physical wasting, or severe and rapid weight loss, night sweats, fevers, chills and weakness.
Decreasing CD4 Count
CD4 cells, also known as T-cells, are the workers of the immune system. These cells seek out and destroy foreign bacteria, viruses and toxins that may harm the body. A healthy immune system replenishes the CD4 cells as they die, keeping the level around 500 to 1000 cells at any given time. AIDS.gov notes that AIDS is typically diagnosed when the CD4 cell count drops to 350 or less. At this time, the body is no longer able to fight any invasion.
Opportunistic Infection
Certain infections are known to take advantage of a weakened immune system and are the hallmark of the AIDS diagnosis. AIDS.gov states that a diagnosis of HIV and one opportunistic infection signals an AIDS diagnosis. Healthy individuals without AIDS may get these infections, including thrush, recurrent herpes or cancers. Individuals diagnosed with AIDS do not have the immune function to fight infection that can be deadly. The final stage of AIDS, prior to death, is sometimes marked by an opportunistic infection called pneuomocystis carinii, a deadly form of pneumonia.
