What Causes Alzheimer's Disease?

Medically reviewed by Karen Foster, LPC
Updated April 16, 2024by BetterHelp Editorial Team

Alzheimer's and other forms of dementia are brain diseases that cause degenerative loss of function in the brain and body. These conditions can be scary for those impacted and their loved ones. Understanding the potential causes of Alzheimer's may help you understand the potential support options available to you.

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Are you or a loved one struggling with Alzheimer’s?

What is Alzheimer's disease? 

Alzheimer's is a neurological disorder that causes brain cells to die over time, leading to memory loss and decreased brain function. The symptoms of Alzheimer's start mild but grow more severe as time progresses, ending in fatality. 

Alzheimer's is the most common form of dementia, making up 60% to 70% of dementia cases worldwide. Nearly six million people in the US live with Alzheimer's, and it is expected to exceed 13 million by 2050. 

What causes Alzheimer's disease?

The leading cause of Alzheimer's is brain cell death, like other forms of dementia. It is a degenerative disease that progressively worsens as time passes. A person with Alzheimer's has fewer nerve cells and connections in their brain, and those cells and connections continue to die off as time passes.

Autopsies performed on those with the disease show that the brain contained tiny deposits, called plaques, between dying brain cells and tangles in the nerve cells accumulated on the brain tissue. The plaques are made of a beta-amyloid protein, while the tangles are composed of another protein called tau.


Symptoms of Alzheimer's disease

Early symptoms of Alzheimer's disease can include the following: 

  • A decline in the ability to remember new information causes the person to repeat questions or conversations, misplace items, forget appointments, or get lost on an otherwise familiar trip
  • Difficulty with reasoning, judgment, and handling more complex tasks, such as understanding safety risks, managing finances, making decisions, and planning more in-depth activities
  • Problems with vision that are not due to eyesight, such as an inability to recognize faces or find objects within plain sight
  • Difficulty with speaking, reading, or writing
  • Changes in personality or behavior include apathy, a loss of empathy, erratic mood swings, withdrawal, or other forms of socially unacceptable behavior

Memory loss and language difficulties are the most prominent early symptoms of Alzheimer's disease. The key to Alzheimer's symptoms is that they take months or years to worsen rather than hours or days. If cognitive functions are declining faster, this may signal a medical emergency. 

Is Alzheimer's disease genetic?

If you know someone in your family who has or has had Alzheimer's, you may have asked yourself, is Alzheimer's disease hereditary?

Some people are born with a gene called APOE-e4, which is linked to people over 55 developing Alzheimer's disease. However, the test is controversial because its results have proven unreliable. In about 5% of cases, individuals with a history of Alzheimer's disease in their families can experience early-onset Alzheimer's disease, affecting those aged 30 to 60.

Does Alzheimer's skip a generation?

No, Alzheimer's does not skip a generation. If you have inherited the APOE-e4 gene (the "Alzheimer's gene") and live long enough, you may also develop the disease. However, many forms of Alzheimer's disease are not inherited.

How does Alzheimer's cause death?

It may be difficult to understand how Alzheimer's disease causes death. This condition causes death in the same way as another progressive disease causes death, which involves complications due to the condition. For instance, as patients lose control over their motor skills, they may become bedridden. Bedridden people can develop blood clots, and when a blood clot loosens, it can travel to the heart, lungs, or brain, which may cause death. 

Alzheimer's disease causes people to lose the ability to move and eat for themselves, in addition to other forms of disability. If these individuals are not cared for, such disabilities can have devastating consequences. At the end of the disease, many people require round-the-clock care. 

Alzheimer's disease vs. dementia

Dementia is the more general term under which other neurological issues fall. Dementia refers to a range of conditions with a loss of cognitive function. Alzheimer's is the most common form of dementia; others include Huntington's disease, Creutzfeldt-Jakob disease, and Parkinson's disease. A person can experience more than one type of dementia.

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Are you or a loved one struggling with Alzheimer’s?

How is Alzheimer's diagnosed?

There is no single test used to diagnose Alzheimer's. Doctors analyze an individual's symptoms, review their medical history, and attempt to rule out any other conditions before determining a diagnosis. They may also test the person's neurological functions, such as balance, reflexes, and senses. Other tests may be performed, such as a CT or MRI of the brain, blood or urine test, or depression screening.

Once the patient has passed these tests, the doctor will move on to cognitive and memory tests to analyze the individual's ability to think clearly and recall information. 

Treatment for Alzheimer's disease

There is no cure for Alzheimer's. Once brain cells die, there is no way to reverse the process. However, people with Alzheimer's can enjoy an improved quality of life with the appropriate treatment. For instance, support groups can go a long way, as can activities that keep the mind keen.

There are no medications to cure Alzheimer's, but some medications can improve a person's quality of life by reducing symptoms or slowing disease progression. Quality-of-life care can become more critical as the person loses their ability to live independently without outside assistance.

Risk factors and preventative care

There is no definitive way to prevent the development of Alzheimer's. Certain risk factors may be unavoidable, such as aging, having Alzheimer's in one's family history, or being born with specific genes. Certain activities, like exercising regularly, keeping conditions like cardiovascular disease and diabetes in check, and quitting smoking, may prevent the onset of Alzheimer's. Eating a healthy diet and participating in lifelong learning activities that keep the brain keen is essential.

It can also be helpful to know the risk factors associated with developing Alzheimer's disease, though there may be no way to avoid them. For example, exposure to certain environmental chemicals, such as pesticides, toxic metals, or industrial chemicals, may hasten Alzheimer's onset, as can repeated or severe traumatic brain injuries (TBI). An average TBI can double a person's risk of developing dementia, while a severe TBI raises it by 4.5 times the average likelihood.

To reduce the chances of experiencing a TBI, wear a seatbelt in the car and proper equipment to safeguard your head while playing contact sports. Follow the directions given by your doctor to ensure that you get rest to expedite proper recovery following an injury.

Caregiver support

Taking care of someone with Alzheimer's can be challenging, and it can be essential for caregivers to receive support. In addition, living with Alzheimer's can cause several challenging emotions to arise. The Alzheimer's Association has resources available. However, if you face barriers to receiving care, such as disability or financial challenges, you may also benefit from online therapy through a platform like BetterHelp. 

Online therapy can have many benefits for caregivers and their loved ones. Because you attend treatment remotely, you don't have to worry about commuting to an office and won't be put on a waiting list. When you sign up for online treatment, you'll be matched with an available therapist to get started. 

Research shows that online therapy is effective. One study showed online therapy could significantly decrease the impact of stress and chronic fatigue on participants, leading to a 50% reduction in symptoms for several mental health conditions, including anxiety and depression. 


The cause of Alzheimer's is not completely clear, but research is ongoing, and more treatment options are being studied. If you're caring for someone with Alzheimer's, talking to a therapist can help you take care of your own mental help to help your loved one to the best of your ability. You can also talk to a therapist if you're living with Alzheimer's and want to discuss your experiences with the condition.
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