Not all people with memory problems have Alzheimer's disease. Some people may experience mild forgetfulness, which can be a normal part of aging. They may notice that it takes longer to learn new things, they don't remember information as well as they did, or they misplace their keys. Other memory problems may be related to health issues that are treatable. For example, medication side effects, vitamin B12 deficiency, or liver or kidney disorders can lead to memory loss or possibly dementia. Emotional problems, such as stress, anxiety, or depression, can also make a person more forgetful and may be mistaken for dementia.

However, for some older people, memory problems are a sign of a serious problem, such as mild cognitive impairment, or MCI. People with this condition have more memory problems than normal for people their age, but their symptoms are not as severe as in Alzheimer's. They are able to carry out their normal daily activities. They usually do not have Alzheimer's symptoms like confusion, attention problems, and difficulty with language. Signs of MCI include misplacing things often, forgetting to go to important events and appointments, and having trouble coming up with desired words. People with MCI are more likely to go on to develop Alzheimer's disease than are people without MCI.

Alzheimer's Disease

Alzheimer's disease is not a normal part of aging. It is a brain disease that slowly destroys memory and thinking skills and, eventually, the ability to carry out the simplest tasks. Memory problems are one of the first signs of Alzheimer's. People may have trouble remembering things that happened recently or names of people they know. Over time, symptoms will most often get worse, and problems can include getting lost, repeating questions, and taking longer than normal to finish daily tasks. As the disease progresses, people may have trouble learning new things, recognizing family and friends, and communicating. Eventually, they need total care.

Dementia is a loss of thinking, remembering, and reasoning skills that interferes with daily life and activities. Alzheimer's disease is the most common cause of dementia among older people. Other causes of dementia include vascular dementia (a blood vessel disease in the brain), Parkinson's disease, Pick’s disease (front temporal dementia) and Lewy body disease.

An elderly man with a hand on his shoulder

According to the National Institutes of Health, as many as 5.1 million people in the US may have Alzheimer's disease. Symptoms usually begin after age 60, and the risk of developing Alzheimer's increases with age. People in their thirties and forties also may get Alzheimer's disease, but it is much less common.

Alzheimer's disease varies from person to person. It can progress faster in some people than in others. In general, Alzheimer's takes many years to develop, becoming increasingly severe over time. As the disease goes on, memory gets worse. People may have problems recognizing family and friends or learning new things. People in this moderate stage of Alzheimer's may behave differently, too, becoming restless, agitated or angry, or they may wander. As Alzheimer's disease becomes more severe, people lose the ability to communicate. They may sleep more, lose weight and have trouble swallowing or controlling their bladder and bowel. Eventually, they need total care.

An early, accurate diagnosis of Alzheimer's disease helps patients and their families plan for the future. It gives them time to discuss care options and make legal and financial arrangements while the patient can still take part in making decisions. And even though no drug can stop or slow the disease, early diagnosis offers the best chance to treat the symptoms.

Alzheimer's disease is named after Dr. Alois Alzheimer, a German doctor. In 1906, Dr. Alzheimer noticed changes in the brain tissue of a woman who had died of an unusual mental illness. He found many abnormal clumps (amyloid plaques) and tangled bundles of fibers (neurofibrillary tangles) that today are considered the main signs of Alzheimer's disease.

Scientists have found other brain changes in people with Alzheimer's disease. As more and more plaques and tangles form, healthy nerve cells begin to work less well and lose their ability to communicate with each other. Eventually, they die. As nerve cells die, brain tissue begins to shrink.

Causes and Risk Factors

The causes of Alzheimer's disease are not fully understood. For most people there probably is not one single cause, but a combination of genetic, environmental and lifestyle factors that affect each person differently, including:

  • Increasing age is the most important known risk factor for Alzheimer's disease. The number of people with the disease doubles every five years beyond age 65.
  • Family history is another risk factor for Alzheimer's disease. A rare form of Alzheimer's disease, called early-onset familial Alzheimer's, is inherited. It occurs between the ages of 30 and 60, and is caused by mutations or changes in certain genes.

Lowering Your Risk

In addition to genetics and studies of pathways in the brain affected by Alzheimer's disease, scientists are also studying lifestyle factors, such as diet, exercise and social engagement. They are finding more clues that some health conditions, like heart disease, high blood pressure, diabetes and obesity, are related to Alzheimer's disease. Research suggests that these steps might lower your risk of developing Alzheimer's disease:

  • lowering high blood pressure and high cholesterol levels
  • controlling diabetes
  • being physically active
  • eating a healthy diet
  • engaging in activities that stimulate the mind

More studies are being done to see which health and lifestyle factors directly affect the chances of developing Alzheimer's. Many of these factors are known to lower the risk for other diseases and help maintain and improve overall well-being, so they are good to do anyway. Currently, there are no treatments, drugs, or pills that can prevent Alzheimer's disease.


Doctors can only make a diagnosis of "possible" or "probable" Alzheimer's disease while a person is alive. Doctors with special training, including geriatricians, geriatric psychiatrists and neurologists, can diagnose Alzheimer's disease correctly up to 90 percent of the time. Doctors use several tools to diagnose Alzheimer's disease:

  • a complete medical history with questions about the person's general health, past medical problems, family health, and any difficulties carrying out daily activities
  • medical tests, such as tests of blood, urine or spinal fluid
  • tests to measure memory, problem solving, attention, counting, and language skills
  • brain scans that allow the doctor to look at a picture of the brain to see if anything does not look normal

Sometimes, test results help doctors to rule in or rule out other possible causes of the person's symptoms. Health issues such as thyroid problems, drug reactions, depression, brain tumors, and blood-vessel disease in the brain can cause symptoms similar to those of Alzheimer's. Some of these other conditions can be treated successfully.

Today, the only definitive way to diagnose Alzheimer's disease is to find out whether plaques and tangles co-exist in brain tissue. To look at brain tissue, doctors perform a brain autopsy, which is an examination of the brain done after a person dies.


There is no known cure for Alzheimer's disease, but there are treatments that can prevent some symptoms from getting worse for a limited time. The course of Alzheimer's disease - what symptoms appear and how quickly changes occur - varies from person to person. The time from diagnosis to the end of life varies, too. It can be as little as three years if the person is over 80 years old when diagnosed or more than 10 years if the person is younger. Anyone with Alzheimer's should be under a doctor's care and see a neurologist, psychiatrist, family doctor, internist or geriatrician as needed. The doctor can treat the person's physical and behavioral problems and answer questions that the patient and family may have.

No treatment can stop Alzheimer's disease; however, drugs are used to treat its symptoms. Drugs may help maintain thinking, memory and speaking skills and help with some behavioral problems for a limited time by regulating certain chemicals in the brain. All drugs have possible side effects, including nausea, vomiting, diarrhea and loss of appetite. Doctor's instructions should be followed, and any unusual symptoms reported right away.


In addition to possible new treatments for Alzheimer's, scientists are looking for ways to prevent the disease. Observational studies that look at possible links between some aspect of a person's lifestyle - such as diet or exercise - and Alzheimer's or dementia have provided some clues.

Food & Diet

Clinical trials are testing whether food or dietary supplements containing antioxidants can delay or prevent the mental decline associated with Alzheimer's disease. Some recent studies suggest that how we eat may be linked to our risk of developing or not developing Alzheimer's disease. Scientists are also looking at the effect that DHA, an omega-3 fatty acid found in some fish, might have on people with Alzheimer's.

Physical Activity

Growing evidence suggests that physical activity might be good for our brains as well as our hearts and waistlines. In one observational study , the risk of Alzheimer's disease was 35 to 40 percent lower in older adults who exercised for at least 15 minutes three or more times a week than in those who exercised fewer than three times a week. These results are promising, and more clinical trials are underway to find out if physical activity can actually prevent or delay Alzheimer's.

Brain Activity

Observational studies have also found that keeping the brain active may be associated with a reduced risk of Alzheimer's. Researchers have found that mentally stimulating activities like reading newspapers, playing games and visiting museums may help keep your brain sharp. In one study, the risk of developing Alzheimer's was 47 percent lower on average for participants who did mentally stimulating activities than for those who did them the least frequently. Researchers concluded that certain mental activities can produce lasting improvements in older adults' thinking skills and quality of life.

Relationships & Community

Interacting with friends might help prevent or slow down mental decline. Data from the NIA-funded Chicago Health and Aging Project, an observational study, showed that people who socialized a lot had higher thinking skills than people who did not. More research is needed to see if socializing does, in fact, play a direct role in preventing Alzheimer's disease.

Alzheimer's Disease Clinical Trials Database

To make it easier for people to find out about studies, the National Institute on Aging (NIA) maintains the Alzheimer's Disease Clinical Trials Database. It lists clinical studies for Alzheimer's disease that is sponsored by the federal government and private companies. This database can be used to search for a study on a certain topic or in a certain geographic area.

Visit the Alzheimer's Disease Clinical Trials Database