Alzheimer’s disease typically progresses slowly in three general stages: early, middle and late (sometimes referred to as mild, moderate and severe in a medical context). Since Alzheimer’s affects people in different ways, each person may experience symptoms — or progress through the stages — differently.
Overview of disease progression
The symptoms of Alzheimer’s worsen over time, but because the disease affects people in different ways, the rate of progression varies. On average, a person with Alzheimer’s lives four to eight years after diagnosis, but can live as long as 20 years, depending on other factors.
Changes in the brain related to Alzheimer’s begin years before any signs of the disease. This period is referred to as preclinical Alzheimer’s disease.
The following stages provide an overall idea of how abilities change once symptoms appear and should be used as a general guide. Stages may overlap, making it difficult to place a person with Alzheimer’s in a specific stage.
In the early stage of Alzheimer’s, a person may function independently. He or she may still drive, work and be part of social activities. Despite this, the person may feel as if he or she is having memory lapses, such as forgetting familiar words or the location of everyday objects.
Friends, family or others close to the individual begin to notice difficulties. During a detailed medical interview, doctors may be able to detect problems in memory or concentration. Common difficulties include:
- Problems coming up with the right word or name.
- Trouble remembering names when introduced to new people.
- Challenges performing tasks in social or work settings.
- Forgetting material that was just read.
- Losing or misplacing a valuable object.
- Increasing trouble with planning or organizing.
Middle-stage Alzheimer’s is typically the longest stage and can last for many years. As the disease progresses, the person with Alzheimer’s will require a greater level of care.
You may notice the person with Alzheimer’s confusing words, getting frustrated or angry, or acting in unexpected ways, such as refusing to bathe. Damage to nerve cells in the brain can make it difficult to express thoughts and perform routine tasks.
At this point, symptoms will be noticeable to others and may include:
- Forgetfulness of events or about one’s own personal history.
- Feeling moody or withdrawn, especially in socially or mentally challenging situations.
- Being unable to recall their address or telephone number or the high school or college from which they graduated.
- Confusion about where they are or what day it is.
- The need for help choosing proper clothing for the season or the occasion.
- Trouble controlling bladder and bowels in some individuals.
- Changes in sleep patterns, such as sleeping during the day and becoming restless
- An increased risk of wandering and becoming lost.
- Personality and behavioral changes, including suspiciousness and delusions or compulsive, repetitive behavior like hand wringing or tissue shredding.
WANDERINGSix out of 10 people with Alzheimer’s will wander and become lost. People can wander or become confused about their location at any stage of the disease. If not found within 24 hours, up to half of those who get lost risk serious injury or death. Visit alz.org/safety to learn about MedicAlert® + Alzheimer’s Association Safe Return®, a 24-hour emergency response service that provides assistance when a person with dementia becomes lost or has a medical emergency.
In the final stage of the disease, individuals lose the ability to respond to their environment, carry on a conversation and, eventually, control movement. They may still say words or phrases, but communicating pain becomes difficult. As memory and cognitive skills worsen, significant personality changes may occur and extensive help with daily activities may be required.
At this stage, individuals may:
- Need round-the-clock assistance with daily activities and personal care.
- Lose awareness of recent experiences as well as of their surroundings.
- Experience changes in physical abilities, including the ability to walk, sit and, eventually, swallow.
- Have greater difficulty communicating.
- Become increasingly vulnerable to infections, especially pneumonia.