Houston Methodist. Leading Medicine.
Houston Methodist. Leading Medicine

Nantz National Alzheimer Center

Stages of Alzheimer's Disease

Each patient with Alzheimer’s disease is unique, and each patient’s illness may progress at a different pace. Stages are used to provide general information about how the disease tends to advance.


You may have begun noticing subtle changes in your loved one’s behavior, forgetfulness and mood. You may have “covered” for him or her, explaining away unusual conduct or questions, to yourself or others. It may seem scary to think about taking your loved one to a doctor and discussing these changes.

Alzheimer’s is a disease that needs attention, care, treatment and research. The earlier someone gets medical attention, the more we can do to determine the cause of the symptoms – whether it is AD or some other cause. If your loved one does have AD, we can begin treatment that might help slow the progression of the disease, and we can get you, the caregiver, much-needed help and support.

Suffering from AD or having a loved one with AD should not be a cause for shame or embarrassment. AD is a disease just like any other disease. No one would care for someone with cancer or heart disease without the help of extensive, accurate medical attention. The same goes for neurological diseases like Alzheimer’s. Having a disease of the brain is not a personal weakness. It is simply an illness.

Please reach out for help. Doctors with special training in memory loss and geriatrics can help determine the cause, work with you on a treatment plan, and connect you to the support that is helpful, and possibly necessary, to care for your loved one.

Mild Cognitive Impairment (MCI)

MCI is the stage between the normal cognitive decline of aging and serious decline of dementia. It is associated with issues relating to memory, language and judgment that are more severe than normal age-related changes. People with MCI may be aware of their own decline in memory and function. These changes are frustrating and noticeable, but are not severe enough to restrict a person’s regular daily work. People with MCI have an increased risk of developing AD or other types of dementia. 

Early Stage or Mild Alzheimer’s disease

For patients with early stage AD, problems with memory and thinking continue, and additional cognitive issues arise. Patients can exhibit common behaviors:

  • getting lost
  • misplacing keys or other important items in unusual places
  • having trouble handling money, such as balancing a checkbook or making change
  • not realizing he/she is repeating questions
  • being unable to follow a recipe
  • needing more time to complete normal daily tasks

People with mild AD might stop doing things that they have always enjoyed, like playing cards, volunteering or leaving the house alone. This could be because they know that something is wrong and are having trouble compensating to hide the problems from others. It could also be due to changes in chemical messengers in the brain that can alter mood and personality.

As a caregiver, it is not only important but vital to take care of yourself. Caring for anyone diagnosed with a disease can take a toll on the caregiver. It is crucial that the caregiver remains healthy – physically, mentally and emotionally. Please consider allowing others to help from the beginning. It is impossible to do all of this alone.

Middle Stage or Moderate Alzheimer’s disease

Changes in behavior and the need for continuous attention mark moderate AD. Memory problems increase.

Damage spreads to other parts of the brain, to areas that control language, reasoning, sensory processing and conscious thought.  Patients may begin to have problems recognizing family and friends. They may have trouble recalling their addresses, phone numbers, what day it is or where they are. They may wander, possibly looking for a place that feels like “home.”

Confusion can increase as the person with AD finds it harder to learn new things, cope with new situations, and perform activities that involve even a few familiar steps, such as getting dressed. They may become suspicious, restless or agitated, especially in the evening.

Patients may exhibit some common behaviors:

  • telling the same story over and over
  • using words that don’t make sense
  • arguing about taking a bath or taking medications
  • making up stories to fill in gaps of memory
  • mistaking one friend for another
  • sleep patterns change
  • wandering around the house or trying to leave the house to go “home”
  • acting aggressive or agitated in the evening, also known as sundowning

Changes in how your loved one acts can be confusing and frustrating to you as a caregiver and loved one. Environmental factors as well as disease progression can be causes of behavioral changes. It is important to get help and seek support. See our Resource Links

Late Stage or Severe Alzheimer’s Disease

Plaques and tangles have spread throughout the brain, affecting movement, communication, ability to recognize family members and friends, and memories of the patient’s own life events. Patients with severe AD are completely dependent on others for their care. Muscles atrophy, taking away patients’ abilities to walk, sit up, or hold their heads up.

Patients with late stage AD exhibit common behaviors:

  • inability to speak coherently
  • inability to dress, get out of bed, bathe or use the bathroom without assistance
  • impaired swallowing function
  • loss of bladder control

Characteristics of each stage of AD may overlap, and progression of the disease can happen at different rates for different individuals with AD. At each stage, it is very important for you as the caregiver to seek help and make time for yourself, your health and your wellbeing. That may seem impossible, but there are organizations that can help at each level. It is not selfish to take time for yourself. It is crucial and valuable for both yourself and your loved one.