People with Alzheimer’s disease experience memory loss and cognitive difficulties. When symptoms begin after age 65, it’s considered late onset Alzheimer’s.

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When Alzheimer’s disease begins after age 65, it’s considered late onset Alzheimer’s disease. It’s the most common cause of late onset dementia and is most often characterized by problems with short-term and long-term memory.

Alzheimer’s dementia stems from a buildup of toxic proteins in the brain that causes the death of nerve cells and interferes with communication between existing nerve cells.

There’s currently no cure for Alzheimer’s disease, but there are treatments and lifestyle behaviors that may help slow its progression.

Late onset Alzheimer’s disease is defined as Alzheimer’s disease that develops when someone is 65 or older. Most people with Alzheimer’s develop it after 65 years.

The brain changes that lead to late onset Alzheimer’s start occurring years before the first symptoms appear. Alzheimer’s disease that develops before 50 years or age is called early onset Alzheimer’s.

Only about 5% of people with Alzheimer’s disease have early onset Alzheimer’s, which usually develops when someone is between ages 40 and 50 — though people may also develop Alzheimer’s between the ages of 50 and 65.

Late onset Alzheimer’s disease is the same disease as early onset, and there’s no clear risk factor or test that explains why some people start having symptoms later than others.

In the earliest stages of late onset Alzheimer’s disease, symptoms tend to be limited to memory problems and confusion. People might get lost driving on familiar roads or forget doctors’ appointments or deadlines to pay certain bills. They may use poor judgment and have difficulty making plans and decisions.

Symptoms of late onset Alzheimer’s disease are progressive and may affect:


As the disease progresses, memory problems can become more sudden. A person with late onset Alzheimer’s might ask a question that was just answered moments ago or repeat a story within a short amount of time.


Sensory changes also start to take place. For example, someone with Alzheimer’s disease may not be able to identify certain familiar scents or tastes. Recognizing faces and voices may become inconsistent.


Later on, personality changes become more obvious. A person with advanced late onset Alzheimer’s may not recognize family members, or they may insist relatives or friends who have passed away are still alive.


It’s also common for someone with advanced Alzheimer’s to become easily agitated, anxious, or aggressive. Sometimes these changes are due to fear and frustration around their inability to remember certain people and events or understand what’s going on around them.

As the disease continues to affect an individual, thinking skills and mood, personality, and behavior changes often have causes not obvious to caregivers and those around them.

Caregivers need support too

If you’re a caregiver of a loved one living with Alzheimer’s disease, you’re likely making sacrifices in your time, finances, and even your own health.

Caregivers of people with Alzheimer’s are primarily women — according to a 2018 Healthline survey, two-thirds of all unpaid caregivers are women. They’re typically the spouses or adult children of those they care for.

If you’re a caregiver for a loved one with Alzheimer’s, you likely need help. From financial assistance to respite care, here are resources to help you find assistance:

Financial support:

Respite care:

Emotional support:

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The primary causes of Alzheimer’s disease, no matter when it develops, are buildups of two proteins in the brain: tau and beta-amyloid. Known causes of Alzheimer’s disease include:

  • Tau and beta-amyloid proteins: The protein tau forms tangles between brain cells (neurons), making communication and signaling between the cells more difficult and eventually impossible. The protein beta-amyloid forms plaques or clumps within neurons, destroying the cells from within.
  • Genetics: There also appears to be a genetic component to Alzheimer’s disease. The condition tends to run in families, so if you have one first degree relative with the disease, your chances of having it one day are increased.
  • APOE-e4 gene: Research suggests that a type of APOE gene has the strongest influence on a person’s risk of developing Alzheimer’s disease. Everyone inherits some form of the gene, but the APOE-e4 gene seems to have the biggest impact. It may be present in up to 65% of individuals with Alzheimer’s disease, according to the Alzheimer’s Association.

Gene testing for the APOE gene or other genes associated with Alzheimer’s may be advisable if you know the disease runs in your family.

As late onset Alzheimer’s progresses, individuals become less able to take care of themselves. Most people with a moderate or severe form of the disease require around-the-clock care, usually at a skilled nursing center or similar facility.

Late in the disease’s course, complications that impact an individual’s health develop, such as:

Pneumonia is a common cause of death for people who have Alzheimer’s disease, as difficulty eating and swallowing fluids can lead to fluid buildup in the lungs.

Treatment options for Alzheimer’s disease are limited. There’s currently no cure or treatment that can reverse the course of the disease. There’s also no vaccine or other reliable means of preventing it.

Treatment options include:


Galantamine, rivastigmine, and donepezil are cholinesterase inhibitors used to treat mild Alzheimer’s.

Two new medications, aducanumab and lecanemab, have recently been approved to treat Alzheimer’s disease. They work by clearing beta-amyloid plaques from the brain. They aren’t considered cures, but they may at least slow cognitive decline associated with Alzheimer’s disease for some people.

Research into other drugs to treat the disease is going on around the world.

Lifestyle changes

For people with late onset Alzheimer’s disease, keeping as healthy a lifestyle as possible, including the following steps, may help delay worsening symptoms:

  • eating a balanced diet
  • engaging in cognitively stimulating activities, such as puzzles, crafts, and music
  • exercising regularly
  • getting regular social interaction
  • sleeping 7 to 9 hours a night

The timing of Alzheimer’s disease progression can be hard to predict. The condition is often categorized into three stages: mild, moderate, and severe.

The time a person spends in each stage differs, but in general, a person lives 4 to 8 years with Alzheimer’s disease after diagnosis. That number can be as high as 20 years, according to the Alzheimer’s Association.

Ultimately, Alzheimer’s is a fatal disease. Because late onset Alzheimer’s tends to develop later in life, many people with the condition also have other health problems. For this reason, most people with late onset Alzheimer’s usually die of another cause.

A neurologist or neuropsychiatrist may diagnose late onset Alzheimer’s disease by reviewing symptoms, usually by talking with the individual and a spouse, relative, or someone close to that person who could elaborate on signs of cognitive decline.

Tests that may be used to help diagnose Alzheimer’s disease include:

There’s no known means of preventing late onset Alzheimer’s. It’s not always clear why a person develops the disease. Health experts recommend people try to prevent other causes of brain changes by:

  • eating a brain-healthy diet such as the Mediterranean or MIND diets
  • getting sufficient sleep
  • limiting or avoiding alcohol consumption
  • managing blood sugar levels
  • managing stress
  • quitting smoking, if relevant
  • staying cognitively challenged through hobbies, social interaction, puzzles, and other activities
  • staying physically active

Is memory loss always the first symptom of late onset Alzheimer’s disease?

While memory loss is the most well-known symptom of Alzheimer’s disease, other problems, such as difficulty with decision making or learning new information, may appear before obvious memory problems surface.

Does late onset Alzheimer’s disease progress faster than early onset?

Research suggests that memory and thinking skills decline faster with early onset Alzheimer’s disease compared with late onset.

Is Alzheimer’s disease a common cause of death?

It’s the sixth-leading cause of death in the United States, according to the Centers for Disease Control and Prevention (CDC).

Late onset Alzheimer’s disease is the most common type of dementia and can affect anyone ages 65 and older. Though memory loss is the most well-known symptom, Alzheimer’s disease actually causes a range of thinking skills problems and other health concerns.

If you or someone you know starts to experience trouble with memory, planning, judgment, or confusion or starts to exhibit unusual personality changes later in life, a conversation with a doctor about a dementia screening may be appropriate.