Most people today know someone with Alzheimer's disease. That's not too surprising, since more than 5 million Americans are living with the disease, which is the sixth leading cause of death in the U.S. Hauntingly, one American develops the disease every 66 seconds [source: Alzheimer's Association].
Alzheimer's is a progressive disease that attacks the brain, causing problems with memory, thinking and behaviors. The most common form of dementia, patients typically develop the disease when they're 65 or older, and it progresses slowly and steadily over a period of about four to 20 years. Some people develop early-onset Alzheimer's, which strikes people in their 40s and 50s. There's no cure for Alzheimer's, although there are medications to treat its symptoms [source: Alzheimer's Association].
Alzheimer's was recognized as the most common form of dementia in 1976, although the biggest boost in its awareness and visibility probably came in 1994, when former U.S. President Ronald Reagan announced he had been diagnosed with the disease. Alzheimer's was first described back in 1906 by Aloysius "Alois" Alzheimer, a German psychiatrist known for his skill in linking various symptoms with microscopic changes in the brain.
Alzheimer had a patient, a woman in her 50s, whom he described as Auguste D., with severe memory loss and paranoid suspicions about her family. After her death, an autopsy showed her brain had shrunk significantly, and she had strange plaque deposits in and around her nerve cells. These symptoms had previously only been seen in the elderly. Alzheimer died in 1915, not knowing how widespread his discovery would become [sources: Alzheimer's Association, Alzheimer's Disease International].