When you think of dementia, you may think about Alzheimer’s disease. While Alzheimer’s is the most common cause of dementia, there are also many others.
There are many causes of dementia. Here, we look at the most common causes alongside treatment options.
Dementia is a general term for symptoms affecting memory, thinking, and daily function. It is not a regular part of aging, and can result from several different medical conditions. Symptoms include:
- memory loss
- difficulty with language
- problem-solving challenges
- changes in behavior
Dementia symptoms are progressive, meaning they worsen over time. Treatment of dementia will depend on its cause.
Most common causes of dementia
The most common causes or types of dementia include Alzheimer’s disease, vascular dementia, Lewy body dementia, frontotemporal dementia, and mixed dementia. Here is how each of these conditions affects a person, plus their treatment options.
Alzheimer’s disease is the most common form of dementia, and may be responsible for between 60% to 80%of all cases. In 2025, it’s estimated that 7.2 million people in the United States age 65 years and older have Alzheimer’s disease. Of these, 74% are age 75 or older.
People with Alzheimer’s start to lose their cognitive functioning, like thinking, remembering, and reasoning. This eventually affects their behaviors, causing them to lose the ability to perform simple daily tasks such as eating and walking. For most people, symptoms of Alzheimer’s start to appear in their mid-60s, and worsen over time.
Alzheimer’s is caused by changes in the brain, including buildups of proteins called amyloid plaques and tau tangles. This is likely due to a combination of genetic, lifestyle, and environmental factors.
Although there is no cure, treatment for Alzheimer’s focuses on managing symptoms and slowing the progression of the disease. Medications like cholinesterase inhibitors and memantine can help manage the symptoms. Disease-modifying therapies such as lecanemab and donanemab may help slow the progression of early stage Alzheimer’s.
Vascular dementia is the second most common cause of dementia. Vascular dementia can be the result of several small strokes, or it can be due to long-term high blood pressure or hardening of the arteries.
Treatments for vascular dementia focus on improving blood flow to the brain, which can help prevent vascular dementia or slow the progression of dementia. This includes treating underlying conditions with medications to manage high blood pressure or high cholesterol. In addition, a heart-healthy lifestyle that includes a healthy diet and regular exercise can help.
Procedures such as carotid endarterectomy, angioplasty, and stenting may also help improve blood flow to the brain. Sometimes, antidepressants and treatments for Alzheimer’s disease may also help improve some of the symptoms.
Lewy body dementia (LBD) is an accumulation of abnormal protein deposits, called Lewy bodies, in nerve cells. These disrupt brain function, eventually leading to the death of brain cells. People with LBD may have periods of being alert and coherent followed by periods of confusion. They may also experience visual hallucinations or have movement symptoms similar to movements of Parkinson’s disease.
Treatments for LBD may include medications like cholinesterase inhibitors to temporarily reduce some symptoms, medications such as levodopa for movement problems, and physical and occupational therapy.
Frontotemporal dementia is a rare form of dementia that often affects people at a younger age than other forms of dementia, often beginning before age 60. It is linked to abnormal forms or amounts of the proteins TDP-43 and tau. It can lead to behavioral changes, language problems, and difficulty moving.
While there are no treatments to slow the progression of frontotemporal dementia, medications like antidepressants, antipsychotics, or sleep aids can help with mood changes and sleep problems.
Physical, occupational, and speech therapy can also help with movement, daily living activities, and communication problems, respectively.
As the name implies, mixed dementia is caused by more than one type of dementia simultaneously. The most common combinations are Alzheimer’s and vascular dementia, or Alzheimer’s disease and Lewy body dementia. Symptoms will depend on the particular forms of dementia present.
It’s difficult to accurately diagnose mixed dementia. Most people receive a diagnosis with only one type — most commonly Alzheimer’s — and a mixed diagnosis is not made until a brain autopsy after a person’s death. Doctors usually prescribe treatment for the primary diagnosis, such as Alzheimer’s treatments.
There are certain risk factors associated with dementia:
- Age: The risk of dementia increases from the age of 65 onward.
- Family history: A family history of dementia, particularly Alzheimer’s disease, can increase your risk.
- Certain health conditions: Several health conditions are associated with a greater risk of dementia, including:
- high blood pressure
- high cholesterol
- heart disease
- stroke
- hearing loss
- depression
- Lifestyle factors: Some that can increase the risk of dementia include:
- physical inactivity
- smoking
- drinking excess alcohol
- an unhealthy diet
For yourself or a loved one, if you notice memory loss, issues with planning or problem-solving, difficulty with familiar tasks, or shifts in mood or behavior, talk with your doctor. Early diagnosis and treatment can greatly improve quality of life, and in some cases, delay the progression of dementia.
Dementia is a term for symptoms affecting memory, thinking, and daily function. There are many different causes of dementia.
The most common cause of dementia is Alzheimer’s disease. Other common causes include vascular dementia, Lewy body dementia, frontotemporal dementia, and mixed dementia.
While there is no cure for dementia, treatments can help ease symptoms. In some cases, treatments can also delay the progression of dementia.