| Introduction | | | | Scientists do not yet fully understand the causes of |
| Alzheimer's disease is a progressive condition that | | | | Alzheimer's disease. There probably is not one single |
| damages areas of the brain involved in intelligence, | | | | cause, but several factors that affect each person |
| memory, behavior, judgment, and language. It is the | | | | differently. |
| most common form of mental decline in older adults. | | | | |
| Alzheimer's gets worse over time, but the course of | | | | Recent studies indicate that amyloid beta protein |
| the disease varies from person to person. Some | | | | may cause Alzheimer's disease. In healthy people, this |
| people may still be able to function relatively well until | | | | protein can cross the blood-brain barrier (the wall of |
| late stages of Alzheimers disease. Others may lose | | | | blood vessels that feed the brain and regulate the |
| the ability to do daily activities in earlier stages. Over | | | | entry and exit of brain chemicals) and leave the brain. |
| time, Alzheimer's disease causes severe mental and | | | | In people with Alzheimers disease, amyloid beta |
| functional problems and eventually results in death. | | | | protein can't pass through that barrier. As more |
| | | | amyloid beta protein accumulates in a person's brain, |
| Causes | | | | they become more and more mentally disabled. |