Often, someone with dementia recognizes that something is wrong, but fear may keep the person from seeking treatment. As the disease worsens, the person may become nervous, depressed or anxious about the symptoms.

Along with memory loss, a person with dementia may have trouble with complex mental tasks, such as balancing a checkbook, driving, knowing what day it is, and learning new things. Attention, judgment, problem solving, mood and behavior also may change. As the disorder progresses, the person may have difficulty speaking in full sentences, recognizing his or her surroundings, recognizing other people, or handling personal care, such as bathing. In some cases, a person with dementia may experience hallucinations, delusions, agitation, social withdrawal and insomnia.