Gold Member Badge


  • You're all caught up!

What Body Systems Are Affected by Alzheimer Disease?

author image Dr. Tina M. St. John
Dr. Tina M. St. John owns and operates a health communications and consulting firm. She is also an accomplished medical writer and editor, and was formerly a senior medical officer with the U.S. Centers for Disease Control and Prevention. St. John holds an M.D. from Emory University School of Medicine.
What Body Systems Are Affected by Alzheimer Disease?
An older woman is consoling her husband. Photo Credit: monkeybusinessimages/iStock/Getty Images

Alzheimer disease is a chronic, incurable brain disorder characterized by progressive loss of brain tissue and function. The early stages of Alzheimer disease primarily affect intellectual functions. Late-stage Alzheimer disease directly or indirectly affects other body systems. The condition is ultimately fatal. The Alzheimer's Association estimates that up to 5.3 million men and women in the United States are living with Alzheimer disease.

Video of the Day

Central Nervous System

Alzheimer disease is principally a disease of the central nervous system, which includes the brain and spinal cord. Although the cause of Alzheimer disease remains poorly understood, specific brain abnormalities have been identified in patients with the disorder. Amyloid plaques, composed of specific proteins and pieces of dead brain cells, progressively accumulate in the brain tissue. A naturally occurring brain protein known as tau also accumulates abnormally, causing brain cells to malfunction and eventually die.

The loss of functioning brain tissue that occurs with Alzheimer disease initially causes problems with memory and learning. As the disease progresses, intellectual function, personality and mood are increasingly affected. With late-stage disease, patients lose their sense of self and present circumstances. Patients with advanced Alzheimer disease are completely dependent on others for daily care, as they have forgotten how to go about the most basic tasks of daily living. Patients do not recognize loved ones and lose the capacity to contemplate, plan, rationalize, organize and interact with their environment.

Digestive System

Alzheimer disease adversely affects the digestive system in several ways. According to a review published in 2013 in the "Archives of Gerontology and Geriatrics," swallowing difficulties commonly occur in Alzheimer disease, and compared to other types of dementia, these difficulties often occur fairly early in the disease. People often have difficulty eating without choking. Pneumonia remains a common cause of death among people with Alzheimer disease. The onset of pneumonia is frequently associated with swallowing difficulties that lead to the accidental entry of food or liquids into the airways. People living with Alzheimer disease may develop an impaired sense of smell, which also interferes with the sense of taste. Eating may become problematic due to these impairments. Bowel control is also adversely affected with Alzheimer disease. Fecal incontinence occurs in most people with advanced disease.

Neuromuscular System

People with advanced Alzheimer disease lose the ability to use their muscles in purposeful ways. Patients with late-stage disease typically lose their ability to walk. The ability to maintain posture to sit safely in a chair may also be lost. The muscles become increasingly rigid as control of the neuromuscular system declines. Accidental injuries related to declining motor function are common among people with Alzheimer disease.

LiveStrong Calorie Tracker
Lose Weight. Feel Great! Change your life with MyPlate by LIVESTRONG.COM
  • Gain 2 pounds per week
  • Gain 1.5 pounds per week
  • Gain 1 pound per week
  • Gain 0.5 pound per week
  • Maintain my current weight
  • Lose 0.5 pound per week
  • Lose 1 pound per week
  • Lose 1.5 pounds per week
  • Lose 2 pounds per week
  • Female
  • Male
ft. in.



Demand Media