Dementia is defined as a memory disorder involving damage to nerve cells in the brain, resulting in diminished capacity to some aspects of memory and the ability to perform typical activities of daily living. It affects everyone differently, depending upon which area of their brain has been damaged. Dementia is not a normal part of aging.

Alzheimer’s is the most common of the estimated 50+ types of dementia. Other common types include vascular dementia — caused by stroke — and mixed dementia, which is a combination of the two.

Dementia can also be caused by traumatic brain injury, chronic alcoholism or encephalitis. It has been found in the later stages of Parkinson’s disease and in those with Lewy Body disease, a variant of Alzheimer’s. Some dementias, such as those caused by a reaction to medications or vitamin deficiencies, may improve with treatment.

How Does Dementia Affect the Body?

Dementia can affect many different systems in the body and the ability of the body to function as a whole, resulting in:

  • Inadequate nutrition. Many people with dementia eventually reduce or stop their intake of nutrients. Ultimately, they may be unable to chew and swallow.
  • Pneumonia. Difficulty swallowing increases the risk of choking or aspirating food into the lungs, which can block breathing and cause pneumonia.
  • Inability to perform self-care tasks. As dementia progresses, it can interfere with bathing, dressing, brushing hair or teeth, using the toilet independently and taking medications accurately.
  • Personal safety challenges. Some day-to-day situations can present safety issues for people with dementia, including driving, cooking and walking alone.
  • Death. Late-stage dementia results in coma and death, often from infection.

How Can You Prevent Dementia?

While there's no sure way to prevent dementia, there are steps that might help. More research is needed, but it could be beneficial to:

  • Keep your mind active. Mentally-stimulating activities, such as reading, solving puzzles and playing word games may delay the onset of dementia and decrease its effects.
  • Be physically and socially active. Physical activity and social interaction could delay the onset of dementia and reduce its symptoms. Move more and aim for 150 minutes of exercise a week.
  • Quit smoking. Some studies have shown smoking in middle age and beyond may increase your risk of dementia and blood vessel (vascular) conditions. Quitting smoking might reduce your risk and will improve your health.
  • Get enough vitamin D. Research suggests that people with low levels of vitamin D in their blood are more likely to develop Alzheimer's disease and other forms of dementia. You can get vitamin D through certain foods, supplements and sun exposure. In general, t's a good idea to make sure you get enough vitamin D.
  • Lower your blood pressure. High blood pressure may lead to a higher risk of some types of dementia.
  • Eat healthy. A healthy diet is important for many reasons, but a diet such as the Mediterranean diet — rich in fruits, vegetables, whole grains and omega-3 fatty acids, commonly found in certain fish and nuts — might promote health and lower your risk of developing dementia.

Risk Factors You Can Change

You can take steps to lessen these risks of developing dementia.

  • Heavy alcohol use. If you drink large amounts of alcohol, you might have a higher risk of dementia. Some studies, however, have shown that moderate amounts of alcohol might have a protective effect. Discuss the proper amount with your doctor, not your bartender.
  • Cardiovascular risk factors. High blood pressure (hypertension), high cholesterol, buildup of fats in artery walls (atherosclerosis) and obesity could all increase the risk for dementia.
  • Depression. Although still being researched, some data shows late-life depression may be a factor in the development of dementia.
  • Diabetes. If you have diabetes, you might have an increased risk of dementia, especially if it's poorly controlled.
  • Smoking. Smoking might increase your risk of developing dementia and blood vessel (vascular) diseases.
  • Sleep apnea. People who snore and have episodes where they frequently stop breathing while asleep may have reversible memory loss.

When to See a Doctor

See a doctor if you or a loved one has memory problems or other dementia symptoms. Because some treatable medical conditions can cause dementia-like symptoms listed below. It's important to determine the underlying cause as soon as possible.

Reversing Dementia-Like Conditions

Some causes of dementia or dementia-like symptoms can often be reversed with treatment.

Infections and Immune Disorders

Fever and other side effects of your body’s attempt to fight infection can result in dementia-like symptoms. Multiple sclerosis — a result of the body’s immune system attack its own nerve cells — can also cause dementia.

Metabolic Problems and Endocrine Abnormalities

People with thyroid problems, low blood sugar (hypoglycemia), too little or too much sodium or calcium, or an impaired ability to absorb vitamin B-12 can develop dementia-like symptoms or other personality changes.

Nutritional Deficiencies

Not drinking enough liquids (dehydration); not getting enough thiamine (vitamin B-1), which is common in people with chronic alcoholism; and not getting enough vitamins B-6 and B-12 in your diet can cause dementia-like symptoms.

Reactions to Medications

A reaction to a particular medication or an interaction of several medications can cause dementia-like symptoms.

Subdural Hematomas

Bleeding between the surface of the brain and the covering over the brain, which is common in the elderly after a fall, can cause symptoms similar to dementia.

H3 Anoxia

This condition, also called hypoxia, occurs when organ tissues aren't getting enough oxygen. Anoxia can occur due to severe asthma, heart attack, carbon monoxide poisoning or other causes.