Each individual experiences the symptoms of AD in unique ways. The symptoms of Alzheimer's disease are generally reported to a physician when memory loss becomes apparent. If AD is suspected as the cause, the physician or healthcare specialist will confirm the diagnosis with behavioral assessments and cognitive tests, often followed by a brain scan, if available. The duration of the disease is between 5 and 20 years. The disease can develop many years before it is eventually diagnosed. In its early stages, memory loss, shown as a difficulty to remember recently learned facts, is the most common symptom, although it is often initially misdiagnosed as age-related memory-loss or stress. As the disease advances, symptoms include confusion, anger, mood swings, language breakdown, long-term memory loss, and the general withdrawal of the sufferer as his or her senses decline. Gradually, minor and major bodily functions are lost, leading ultimately to death.

The cause and progression of Alzheimer's disease are not well understood. Research indicates that the disease is associated with plaques and tangles in the brain. No treatment has been found to stop or reverse the disease, and it is not known whether current treatments slow the progression, or simply manage the symptoms. Many preventive measures have been suggested for Alzheimer's disease, but their value is unproven in reducing the course and severity of the disease. Mental stimulation, exercise and a balanced diet are often recommended, both as a possible prevention and as a sensible way of managing the disease.

Because AD cannot be cured and is degenerative, management of the Alzheimer's patient is essential. The role of the main caregiver is often taken by the spouse or a close relative. Caregivers may themselves suffer from stress, over-work, depression, and being physically hit or struck.