Alzheimer’s disease (AD) is a type of dementia. In its early stages, you may experience some memory difficulties and personality changes. Eventually, you may stop recognizing people and develop physical symptoms like incontinence.

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AD affects memory, thinking, and behavior. According to the Alzheimer’s Association, this disease accounts for 60-80% of dementia cases.

AD is more common in people over the age of 65, but some people have early onset AD and show symptoms as early as their 40s or 50s. After a diagnosis, people with the condition can live an average of four to 20 years.

AD is a progressive disease that worsens over time and is the sixth leading cause of death in the United States. Recognizing early symptoms of AD and intervening early helps prolong and improve your quality of life.

Early symptoms of AD can be mild and subtle — so subtle that you may not notice a change in your thinking or behavior.

In the early stage of the disease, you’ll likely have trouble remembering new information. This is because the disease often begins to impact areas of the brain responsible for learning new information. You may repeat questions over and over, forget conversations or important appointments, or misplace objects such as your car keys.

Mild cognitive impairment

Mild cognitive impairment (MCI) can be an early sign of Alzheimer’s disease. The affected person will typically notice difficulties in memory that they didn’t experience before. You may also experience new difficulties in planning or executive function. This can affect tasks that you handled easily before.

Learn more about MCI.

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Occasional memory difficulties can be a typical part of aging, so forgetfulness isn’t necessarily a sign of AD. However, you should speak with your doctor if the problem worsens.

The top 10 warning signs include:

  • misplacing objects and being unable to retrace steps
  • memory loss that affects everyday life (drive to a location)
  • difficulty planning or problem-solving (unable to budget)
  • taking longer to accomplish normal daily tasks
  • losing track of time
  • having trouble determining distance and distinguishing colors
  • difficulty following a conversation
  • poor judgment, leading to bad decisions
  • withdrawal from social activities
  • mood and personality changes and increased anxiety

With time, brain degeneration progresses, and the effects on brain function worsen. Family and friends may recognize changes in your thinking and behavior before you do.

Sometimes, it’s hard to identify memory problems in ourselves. But as the disease progresses, you may recognize telltale symptoms in yourself, such as confusion and a shorter attention span. As more of your brain cells die, you’ll begin to show signs of moderate AD, which include:

  • problems recognizing friends and family members
  • difficulty with language and problems with reading, writing, or working with numbers
  • difficulty organizing thoughts and thinking logically
  • inability to learn new tasks or to cope with new or unexpected situations
  • inappropriate outbursts of anger
  • perceptual-motor problems, such as trouble getting out of a chair or setting the table
  • repetitive statements or movement, and occasional muscle twitches
  • hallucinations, delusions, suspiciousness or paranoia, and irritability
  • loss of impulse control, such as undressing at inappropriate times or places or using vulgar language
  • exacerbation of behavioral symptoms, such as restlessness, agitation, anxiety, tearfulness, and wandering — especially in the late afternoon or evening — called “sundowning”

At this point in the disease, brain plaques (clusters of protein that destroy brain cells) and tangles (dying nerve cells that twist around one another) increase as AD progresses. Both are hallmarks of AD.

This is the final stage of AD. People at this stage lose control of physical functions and depend on others for care. They sleep more often and are unable to communicate or recognize loved ones.

Other symptoms of severe AD include:

Due to the loss of physical function, people with late-stage AD may deal with complications. Difficulty swallowing can result in inhaling liquids into the lungs, which increases the risk of pneumonia. They may also have malnutrition and dehydration. Limited mobility also increases the risk of bedsores.

There are other causes of dementia with symptoms similar to AD. A doctor conducts physical and neurological examinations and uses brain imaging technology to help in the diagnosis of AD. The following list of neurodegenerative diseases can mimic AD:

  • Parkinson’s disease with dementia: This leads to tremors and difficulty with walking, movement, and coordination.
  • Vascular dementia: This occurs from strokes throughout the brain and leads to problems with reasoning, planning, judgment, and memory.
  • Frontotemporal dementia: This affects the temporal and frontal lobes that influence decision-making, behavioral control, emotion, and language.
  • Pick’s disease: This is a rare and permanent form of dementia similar to AD, except it often affects only certain brain areas. You would experience more severe personality and behavior changes than you would with AD, and the disease would progress more rapidly.
  • Supranuclear palsy: is a rare brain disorder that causes serious and progressive problems with control of gait and balance, eye movement, and thinking problems.
  • Corticobasal syndrome (CBS): This occurs when areas of your brain shrink and nerve cells die over time. The result is growing difficulty moving on one or both sides of your body.
  • Hippocampal sclerosis (HS): This is when tissue in the hippocampus part of the brain shrinks and hardens.

Other possible causes of symptoms similar to those of dementia include:

What are the 4 common early signs and symptoms of Alzheimer’s?

In its early stage, AD typically presents with memory and thinking problems, as well as speaking difficulty and mood changes.

How can you tell if someone has dementia or Alzheimer’s?

To identify AD versus another type of dementia, a doctor needs to do an examination, take your symptom history, and send you for various tests. In the early stages, when Alzheimer’s isn’t visible in imaging, it can be hard to tell the difference because different types of dementia can present similarly.

How can I check if I have Alzheimer’s?

If you’re concerned regarding symptoms that seem like they could be Alzheimer’s, make an appointment with your doctor. They will do a neurological exam and may send you for imaging tests.

Talk with a doctor if you or a loved one is experiencing symptoms of AD. Because symptoms worsen over time, it’s important to recognize the possibility of AD. Your doctor can make a diagnosis and assess whether symptoms are mild, moderate, or severe.