Health Topic

Alzheimer's Disease

Alzheimer's disease is a brain disorder that slowly destroys memory and thinking skills. It's the most common cause of dementia among older adults.

Reviewed Reviewed by a registered pharmacistGeneral information

Also called: AD

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia among older people. Dementia is a brain disorder that seriously affects thinking and memory skills. If you have AD, it can impair your ability to reason or learn new skills until it becomes difficult to complete daily activities.

AD begins slowly over many years. It first involves the parts of the brain that control thought, memory, and language. It may be mistaken for normal memory changes with aging. However, AD is not a normal part of aging. The brain changes from the disease lead to symptoms that get worse over time.

People with AD may have trouble remembering recent events or the names of people they know. Behavior may vary from person to person and day to day. AD progresses in stages. Late-onset AD occurs in adults aged 65 and older, which is when most people develop the disease. Early-onset AD happens before age 65, which is not common.

Some symptoms of AD can include:

  • Getting lost in familiar places
  • Repeating the same question
  • Not recognizing family members
  • Having trouble speaking, reading, or writing
  • Not taking care of yourself, such as not bathing or eating poorly

In AD, over time, symptoms get worse. Later on, people with AD may become anxious or aggressive or wander away from home. Eventually, they need total care. This can cause great stress for family members who must care for them.

Researchers don't fully understand what causes AD. Age is the biggest risk factor. Your risk is also higher if a family member has had the disease. Although people who develop Alzheimer's don't always have a history of the disease in their families.

Researchers believe the causes of AD may be a combination of age-related changes in the brain, along with genetic, health, and lifestyle factors. Some medical conditions that are associated with a higher risk of AD include:

  • Hearing loss
  • Depression
  • Mild cognitive impairment
  • Concussion or other traumatic brain injury (TBI)

A related problem, mild cognitive impairment (MCI), causes more memory problems than normal for people of the same age. Many, but not all, people with MCI will develop AD.

Some health conditions can cause memory loss or symptoms like AD. Talk with your health care provider if you're having noticeable changes in your memory. To determine if your symptoms are related to AD and not normal aging or another health condition, your provider may:

  • Review your medical history and any medicines you're taking
  • Conduct tests to check your memory, thinking, and problem-solving skills
  • Ask about changes in behavior or personality
  • Do tests to rule out any medical or mental health conditions
  • Refer you to a provider that specializes in caring for older adults
  • Recommend a neurologist, a doctor who specializes in treating diseases of the brain and nervous system

No treatment can stop the disease. However, some medicines may help keep symptoms from getting worse for a limited time.

You can't change some risk factors, like your age. But changing certain lifestyle factors may promote your brain health and help you live a healthier lifestyle overall. This can include to:

  • Manage chronic health issues such as high blood pressure or hearing loss
  • Get regular physical activity
  • Eat a healthy diet
  • Quit smoking (or don't start)
  • Get enough sleep
  • Develop strong social connections

It sits within Mental Health and Behavior, Older Adults and Brain and Nerves.

The lead U.S. institute for this subject is the National Institute on Aging.

When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.

Research on Alzheimer's Disease

4,198 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

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Symptoms

Treatments and Therapies

Prevention and Risk Factors

Living With

Related Issues

Genetics

Statistics and Research

Clinical Trials

Medical subject headings

Clinicians and researchers index this subject under Alzheimer Vaccines, Alzheimer Disease. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for Alzheimer's Disease, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.