10 Diseases That Used to Be Death Sentences

An AIDS awareness billboard in Blantyre, Malawi. Photofusion/Universal Images Group/Getty Images

You probably know the basics of human immunodeficiency virus (HIV), which causes acquired immunodeficiency syndrome (AIDS). Back in the disease's terrifying heyday of the 1980s and early '90s, even experts knew precious little about how to treat HIV, which is usually transmitted through unprotected anal or vaginal sex or by sharing drug needles [source: CDC]. Common symptoms include rashes, fever, enlarged lymph nodes and a sore throat. Over time, if untreated, a body with HIV loses the ability to fight off infections, which leads to AIDS [source: CDC]. Contracting HIV used to be a death sentence, but not anymore, thanks to the introduction of antiretroviral drugs in the mid-1990s.

"In the early days, people diagnosed with HIV had a life expectancy of about eight years," says John Brooks, M.D., medical officer in the Division of HIV/AIDS Prevention of the Centers for Disease Control and Prevention (CDC). "Today, a person who is promptly diagnosed with HIV and appropriately treated can look forward to a close-to-normal life span." Modern antiretroviral therapy can be administered in as little as one pill per day, eliminating symptoms, but stopping short at actually curing the disease, of course [source: WebMD].

In 2010, AIDS was the seventh leading cause of death among the 25-44 age bracket in the U.S., having peaked at No. 1 in both 1994 and 1995 [source: The Henry J. Kaiser Family Foundation]. Yet, the epidemic is far from over, with about 34 million people in 2014 infected around the globe, often unaware they even have HIV or AIDS [source: amfAR].