Most common form of dementia

Alzheimer’s disease (AD) is the most common form of dementia. The term dementia is used to define brain diseases related to memory loss and diminished cognitive skills. Other types of dementia include:

  • vascular dementia
  • dementia with Lewy bodies
  • mixed dementia
  • Parkinson’s disease
  • Huntington’s disease

An estimated five million Americans now have AD, according to the Alzheimer’s Association.

Nearly twice as many women have AD as men, according to the U.S. Department of Health and Human Services. AD also worsens more quickly in women than it does in men.

Brain shrinkage tends to be more severe in women with AD than in men with the disease. Researchers suggest that brain changes in women with AD may be due to other causes.

Heart disease can raise your risk of getting AD. Other conditions that cause heart disease are also linked to a higher risk of getting AD, including:

  • high blood pressure
  • high cholesterol
  • diabetes
  • poor diet
  • non-active lifestyle

Heart disease may also be a cause of vascular dementia, which results from narrowed blood vessels in the brain. This leads to a decrease in oxygen to brain tissues.

According to the National Institute on Aging (NIA), the more education you have, the lower your risk of getting AD. You have lower odds of getting AD if you keep your brain active in old age by doing activities such as:

  • taking classes
  • learning languages
  • playing musical instruments

Doing group activities or interacting with others also may lower your risk.

The Alzheimer’s Association states that AD is the sixth leading cause of deathin the United States. About one in three seniors die with AD or another form of dementia.

In 2010, the Centers for Disease Control and Prevention (CDC) reported that AD claimed more than 84,000 lives in the U.S. Only heart disease, cancer, some respiratory diseases, stroke, and accidents caused more deaths than AD.

The Alzheimer’s Association also states that AD is the only one of the top 10 causes of death in the U.S. without any methods for preventing, curing, or slowing it down.

Research into a vaccine continues. But so far there are no sure ways to prevent AD from developing. However, medications can help relieve some symptoms.

With an estimated five million Americans who have AD, the cost for treating the disease continues to rise. In 2016 that figure reached about $236 billion, according to the Alzheimer’s Association.

The number of Americans with the disease is expected to increase in the years ahead. It’s estimated that AD may cost the U.S. more than $1 trillion by 2050.

A German doctor named Alois Alzheimer first observed AD in 1906. He described a patient known as Auguste D. who had memory loss and other problems with thinking.

After the patient’s death, Dr. Alzheimer noted that parts of the patient’s brain were shrunken. A psychiatrist who worked with Dr. Alzheimer named the condition in 1910.

A person with AD may lose their sense of smell, according to the National Institutes of Health (NIH). Several studies, including one in the Journal of the Neurological Sciences, suggest that changes in the sense of smell may be an early sign of AD.

It’s important to note that changes in your ability to smell may also be due to other causes such as:

  • Parkinson’s disease
  • brain injury
  • sinus infection

The time it takes for AD to progress varies from person to person, so it’s hard to predict how long someone with the condition will live. The National Institute on Aging (NIA) reports that older adults usually live three to four years with AD. Younger adults who get the disease may live with the condition for 10 years or more.