Scientists continue to unravel the complex brain changes involved in the onset and progression of Alzheimer’s disease. It seems likely that damage to the brain starts a decade or more before memory and other cognitive problems appear. During this preclinical stage of Alzheimer’s disease, people seem to be symptom-free, but toxic changes are taking place in the brain.
Damage occurring in the brain of someone with Alzheimer’s disease begins to show itself in very early clinical signs and symptoms. For most people with Alzheimer’s—those who have the late-onset variety—symptoms first appear in their mid-60s. Signs of early-onset Alzheimer’s begin between a person’s 30s and mid-60s.
The first symptoms of Alzheimer’s vary from person to person. Memory problems are typically one of the first signs of cognitive impairment related to Alzheimer’s disease. Decline in non-memory aspects of cognition, such as word-finding, vision/spatial issues, and impaired reasoning or judgment, may also signal the very early stages of Alzheimer’s disease. And some people may be diagnosed with mild cognitive impairment. As the disease progresses, people experience greater memory loss and other cognitive difficulties.
Alzheimer’s disease progresses in several stages: preclinical, mild (sometimes called early-stage), moderate, and severe (sometimes called late-stage).
Signs of Mild Alzheimer’s Disease
In mild Alzheimer’s disease, a person may seem to be healthy but has more and more trouble making sense of the world around him or her. The realization that something is wrong often comes gradually to the person and his or her family. Problems can include:
- Memory loss
- Poor judgment leading to bad decisions
- Loss of spontaneity and sense of initiative
- Taking longer to complete normal daily tasks
- Repeating questions
- Trouble handling money and paying bills
- Wandering and getting lost
- Losing things or misplacing them in odd places
- Mood and personality changes
- Increased anxiety and/or aggression
Alzheimer’s disease is often diagnosed at this stage.
Signs of Moderate Alzheimer’s Disease
In this stage, more intensive supervision and care become necessary, which can be difficult for many spouses and families. Symptoms may include:
- Increased memory loss and confusion
- Inability to learn new things
- Difficulty with language and problems with reading, writing, and working with numbers
- Difficulty organizing thoughts and thinking logically
- Shortened attention span
- Problems coping with new situations
- Difficulty carrying out multistep tasks, such as getting dressed
- Problems recognizing family and friends
- Hallucinations, delusions, and paranoia
- Impulsive behavior such as undressing at inappropriate times or places or using vulgar language
- Inappropriate outbursts of anger
- Restlessness, agitation, anxiety, tearfulness, wandering—especially in the late afternoon or evening
- Repetitive statements or movement, occasional muscle twitches
Signs of Severe Alzheimer’s Disease
People with severe Alzheimer’s cannot communicate and are completely dependent on others for their care. Near the end, the person may be in bed most or all of the time as the body shuts down. Their symptoms often include:
- Inability to communicate
- Weight loss
- Skin infections
- Difficulty swallowing
- Groaning, moaning, or grunting
- Increased sleeping
- Loss of bowel and bladder control
A common cause of death for people with Alzheimer’s disease is aspiration pneumonia. This type of pneumonia develops when a person cannot swallow properly and takes food or liquids into the lungs instead of air.
There is currently no cure for Alzheimer’s, though there are medicines that can treat the symptoms of the disease.
Symptoms of Mild Cognitive Impairment
Some people have a condition called mild cognitive impairment, or MCI. It can be an early sign of Alzheimer’s. But, not everyone with MCI will develop Alzheimer’s disease. People with MCI can still take care of themselves and do their normal activities. MCI memory problems may include:
- Losing things often
- Forgetting to go to events or appointments
- Having more trouble coming up with words than other people the same age
Learn more about Alzheimer’s disease from MedlinePlus.
For More Information About the Signs of Alzheimer’s Disease
This content is provided by the National Institute on Aging (NIA), part of the National Institutes of Health. NIA scientists and other experts review this content to ensure that it is accurate, authoritative, and up to date.
Content reviewed: May 16, 2017