Q: I find that I forget things. Last week, in the afternoon, I couldn't recall if I had had lunch. When does forgetfulness become a problem? Is there a test?

A: Everyone has memory lapses. The most common are forgetting the names of people when needed or why we walked into a room.

Such occurrences become more common as we age. Memory lapses may worsen when we are distracted, preoccupied, fatigued or suffering from sleep deprivation, stress, or depression.

When problems are much more frequent or different from usual, especially if they affect functioning at work or managing appointments, shopping, housekeeping, or paying bills, they could indicate a health problem. A long list of conditions can affect memory - from imbalances of hormones (such as thyroid hormone) to nutritional deficiencies, depression, concussions, brain tumors, strokes, and Alzheimer's disease. Some are totally treatable, so have these problems evaluated by your primary health-care provider or a specialist.

There are a variety of screening tests and more detailed measures of cognitive function. Some are written; others are computer-based. If a problem is found, your doctor may order blood tests, a brain MRI scan, or other tests.

Some causes of memory loss, like thyroid disease or depression, can be reversed. For others, like ministrokes, care can prevent further decline. If the cause is Alzheimer's, a diagnosis will allow for life planning and participation in research studies of new care that may slow the disease and improve symptoms.