Alzheimer’s disease is a chronic, degenerative condition of the brain cells. Some risk factors can be avoided, but others, such as increasing age and genetic properties, are inevitable. It is now the third most common cause of death in the developed world, with more women than men affected. The first symptom is often an impaired memory for recent events, which can be difficult to distinguish from the normal age-related decline in memory. As the disease progresses, forgetfulness may hinder routine activities such as cooking and household chores. Those affected may be aware of their memory difficulties, so they can deal with the problem by, for example, writing notes or letting someone else manage decisions for them. In the late stages of the disease, the changes in memory and behaviour are marked. Sufferers cannot compensate for their memory lapses and become confused. They may develop paranoid behaviour like jealousy or accusations of theft, and may experience visual hallucinations. People in advanced stages cease to recognize even their family members and close friends. They may also refuse to eat, develop unsteadiness and increasingly lose weight.