Dementia is a loss of brain function that occurs with certain diseases. Alzheimer disease (AD) is the most common form of dementia. It affects memory, thinking, and behavior.
Senile dementia - Alzheimer type (SDAT); SDAT; Dementia - Alzheimer
The exact cause of Alzheimer disease is not known. Research shows that certain changes in the brain lead to Alzheimer disease.
You are more likely to develop Alzheimer disease if you:
The following may also increase the risk:
There are two types of Alzheimer disease:
Alzheimer disease symptoms include difficulty with many areas of mental function, including:
Alzheimer disease usually first appears as forgetfulness.
Mild cognitive impairment (MCI) is the stage between normal forgetfulness due to aging, and the development of Alzheimer disease. People with MCI have mild problems with thinking and memory that do not interfere with daily activities. They are often aware of the forgetfulness. Not everyone with MCI develops Alzheimer disease.
Symptoms of MCI include:
Early symptoms of Alzheimer disease can include:
As Alzheimer disease becomes worse, symptoms are more obvious and interfere with the ability to take care of oneself. Symptoms may include:
People with severe Alzheimer disease can no longer:
Other symptoms that may occur with Alzheimer disease:
A skilled health care provider can often diagnose Alzheimer disease with the following steps:
A diagnosis of Alzheimer disease is made when certain symptoms are present, and by making sure other causes of dementia are not present.
Tests may be done to rule out other possible causes of dementia, including:
The only way to know for certain that someone has Alzheimer disease is to examine a sample of their brain tissue after death.
There is no cure for Alzheimer disease. The goals of treatment are:
Medicines are used to:
Before using these medicines, ask the provider:
Someone with Alzheimer disease will need support in the home as the disease gets worse. Family members or other caregivers can help by helping the person cope with memory loss and behavior and sleep problems. It is important to make sure the home of a person who has Alzheimer disease is safe for them.
Having Alzheimer disease or caring for a person with the condition may be a challenge. You can ease the stress of illness by seeking support through Alzheimer disease resources. Sharing with others who have common experiences and problems can help you not feel alone.
How quickly Alzheimer disease gets worse is different for each person. If Alzheimer disease develops quickly, it is more likely to worsen quickly.
People with Alzheimer disease often die earlier than normal, although a person may live anywhere from 3 to 20 years after diagnosis.
Families will likely need to plan for their loved one's future care.
The final phase of the disease may last from a few months to several years. During that time, the person becomes totally disabled. Death usually occurs from an infection or organ failure.
Contact the provider if:
Although there is no proven way to prevent Alzheimer disease, there are some measures that may help prevent or slow the onset of Alzheimer disease:
Alzheimer's Association website. Press release: First practice guidelines for clinical evaluation of Alzheimer's disease and other dementias for primary and specialty care. www.alz.org/aaic/releases_2018/AAIC18-Sun-clinical-practice-guidelines.asp. Updated July 22, 2018. Accessed April 16, 2020.
Knopman DS. Cognitive impairment and dementia. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 374.
Martínez G, Vernooij RW, Fuentes Padilla P, Zamora J, Bonfill Cosp X, Flicker L. 18F PET with florbetapir for the early diagnosis of Alzheimer's disease dementia and other dementias in people with mild cognitive impairment (MCI). Cochrane Database Syst Rev. 2017;11(11):CD012216. PMID: 29164603 www.ncbi.nlm.nih.gov/pubmed/29164603/.
Peterson R, Graff-Radford J. Alzheimer disease and other dementias. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 95.
Reviewed By: Amit M. Shelat, DO, FACP, FAAN, Attending Neurologist and Assistant Professor of Clinical Neurology, Stony Brook University School of Medicine, Stony Brook, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 09/28/2021.