What disease is caused by the human immunodeficiency virus (HIV)?

The disease caused by the human immunodeficiency virus (HIV) is acquired immunodeficiency syndrome (AIDS). HIV attacks the body's immune system, specifically targeting CD4 T cells, which are crucial for fighting off infections. Over time, if HIV is not treated, it can lead to a significant decline in these immune cells, resulting in the development of AIDS. This progression is marked by a higher susceptibility to opportunistic infections and certain cancers, indicating severe immune system compromise. While hepatitis, syphilis, and tuberculosis are important related health concerns, they are not caused by HIV. Instead, they each have distinct pathogens and mechanisms of illness.