Although Alzheimer's is best known for its memory-robbing effects, the condition is a progressive brain disorder in which abnormal protein deposits build up in the brain, causing cells to die — eventually leading to death.
 

But Alzheimer's is not usually a direct cause of brain death, the LiveScience Website notes.
 

Marc L. Gordon, M.D., chief of neurology at Zucker Hillside Hospital in New York, said complications of the debilitating disease are what usually cause the death of Alzheimer's patients.
 

These complications include infections, such as infections of bedsores that occur when people stay in bed for prolonged periods. Alzheimer's patients also may have difficulty swallowing, and may inhale food, which can result in aspiration pneumonia, Dr. Gordon said. Pneumonia is listed as the cause of death in as many as two-thirds of patients with dementia, according to the Alzheimer’s Society.
 

Alzheimer's patients also can develop fatal blood clots — another complication of being bedridden, Dr. Gordon said.
 

Alzheimer's disease is the sixth-leading cause of death in the United States, according to the Centers for Disease Control and Prevention. In 2010, nearly 85,000 people in the United States died from the disease, the CDC says.
 

But a recent study suggested that the number of deaths from Alzheimer's disease may be five to six times higher than what the CDC reports. That's because death certificates may not list Alzheimer's disease as an underlying condition, but will typically record only the immediate cause of death.