It is important to understand that as we age, some memory loss and cognitive decline is considered to be completely normal. However, Alzheimer’s disease is not a normal part of aging. A common symptom of Alzheimer’s disease is memory impairment. Memory impairment includes both short-term and long-term memory. For example, short-term memory would include the inability to recall what was eaten at breakfast or what was said five minutes ago. As for long-term impairment, an individual would not be able to recall what year they were born.

There are a number of factors that can cause memory loss—not only Alzheimer’s disease. Memory loss can also result from certain medications, drug use, sleep deprivation, stress, as well as vitamin deficiency, thyroid problems and depression. Most of these conditions are reversible; however, Alzheimer’s disease is not reversible and there is no cure.

Mild cognitive impairment (MCI) is defined by the decline in cognitive abilities (memory) and decline in thinking abilities (difficulty completing complex tasks activities) and tends not to interfere with the individual’s day to day life.  MCI is also often defined as a transition stage between the cognitive decline of normal aging and the more serious problems caused by Alzheimer's disease because research indicates that people with MCI have a higher risk of develop dementia, especially Alzheimer's disease. However, about 40 to 60 percent of individuals diagnosed with MCI remain stable or may even get better.  An individual with MCI can experience anxiety, depression, or other emotional difficulties when dealing with the diagnosis; therefore, these conditions should be monitored and discussed with a healthcare professional.

Currently, researchers believe that advanced age is the greatest risk factor for Alzheimer’s disease. Other causes are genetics and family history, oxidative damage to neurons from the overproduction of toxic free radicals, serious head injuries, brain inflammation, and environmental factors.

It is also important to know that there are currently two distinct categories with Alzheimer’s disease. The first category is called either “sporadic” Alzheimer’s or “late-onset” Alzheimer’s.  This type accounts for nearly 95% of all cases of Alzheimer’s disease.  It affects people in older adulthood, usually after age 65, and progresses gradually.  The term “sporadic” speaks to the unpredictability of this type of Alzheimer’s disease.  Only about 20% of families with a history of sporadic Alzheimer’s disease are at greater risk for developing the illness in future generations.  The second type of Alzheimer’s disease is often called “familial” Alzheimer’s disease, or “young-onset” Alzheimer’s disease, and this version affects people who are usually younger than 65 or even as young as in their thirties and forties. . The statistical prevalence of young- onset or early-onset Alzheimer’s disease varies from 6% to 10% of all cases of Alzheimer’s disease. This type has a strong history in families, and the odds of future generations developing the illness are significantly higher than the odds for someone without such a family history.  However, it is very important to know that a family history of early-onset Alzheimer’s disease does not indicate that everyone else in the family will develop the illness, only that the odds are greater. 

The only way to determine whether or not someone has Alzheimer’s disease or any a related disease is to undergo a proper evaluation by a qualified healthcare professional.  This starts with a primary care physician. Through a series of tests, the clinician will try to rule out other possible causes for the current condition.  Typically, the physician will first assess memory and thinking skills by doing a verbal interview.  This interview will allow the doctor to determine if there are any symptoms of dementia, such as memory loss or disorientation. Next, the physician will review medical and psychiatric history to learn if there are any pre-existing conditions that could be contributing to these symptoms, such as depression or thyroid disease.  The physician will then conduct a physical examination and draw blood for testing.  The physical examination is used to decide if there are any medical problems that are currently affecting your ability to think correctly, such as brain tumors and brain injuries, or even dehydration. The blood test is used to assess for several potential problems including medication side-effects, infections, a hormone imbalance, or malnutrition. One of the last steps could be a brain scan that creates an image of the brain.  These include PET, MRI, SPECT, and CT scans.  With all this information, a clinician—a primary care physician, neurologist or other specialist—can make an assessment of the results of all of the previous steps, and compare all of those results in order to diagnose "probable Alzheimer's disease."