Alzheimer's disease is a progressive condition characterized by a loss of cognition, altered behavior, and a loss of functional ability, such as bathing, dressing, toileting, and organizing finances. Family and friends provide nearly three quarters of all care for patients with Alzheimer's disease. This informal care results in significant burden to caregivers. Caregiver burden is the set of physical, psychological or emotional, social, and financial problems that family members may experience when caring for impaired older adults. Caregivers of Alzheimer's disease patients report higher rates of physical symptoms, mortality, depression, and fatigue, as well as adverse effects on employment compared with those who are not caregivers for Alzheimer's disease patients. In many cases, the same family members are responsible for both out-of-pocket expenditures and caregiving duties. For this article, a MEDLINE search using the key words "caregiver and Alzheimer's disease" and "cost and Alzheimer's disease" was performed. The purpose of this article is to review the literature on caregiver burden, the components of caregiver burden, effects of caregiving on the health of caregivers, the cost of Alzheimer's disease on the caregiver and society, and the benefits attainable with treatment.