Symptoms of dementia emerge slowly, worsen over time and restrict your ability to function.

The initial symptom of dementia is usually loss of memory. Although everyone's memory lapses from time to time, the memory loss of dementia is more profound and can affect your ability to function. For example, forgetting where you put your car key is normal, but forgetting how to use the key is a possible symptom of dementia.

If you have dementia, you may recognize that something is wrong but fear may keep you from seeking treatment. As the disease progresses, you may become nervous, depressed or anxious in response to the early symptoms.

Along with memory loss, you may have trouble with more complex intellectual tasks. Examples include balancing a checkbook, driving, knowing where you are and what day it is, and learning new things. Attention, judgment, problem solving, mood and behavior may also change.

As dementia progresses, you may have difficulty speaking in full sentences, recognizing your surroundings, recognizing other people or performing personal-care activities (such as bathing). In some cases, you may experience hallucinations, delusions, agitation, withdrawal and insomnia.

Some medical conditions, such as delirium and depression, can have similar symptoms as dementia. These conditions must be identified early as, unlike dementia, they are reversible. However, if these conditions go untreated, the loss of cognition and memory can be permanent.