Scientists do not know what causes Alzheimer's disease.

Alzheimers Risk Factors

But they have identified several risk factors that increase the likelihood of developing the disease, or suffering non-Alzheimer's cognitive decline. These risk factors run from the well-established to the speculative and highly controversial.

Unfortunately, although many risk factors are clear, there is no sure-fire way to prevent the onset of Alzheimer's disease. But some preventive treatments (such as estrogen for women) are promising. And there are plenty of ways to stay mentally sharp for life -- even though every now and then you might misplace your car keys, forget people's names, or suffer other minor mental lapses. Losing your car keys is no cause for alarm. The time to get concerned is when you find them, but have no idea what to do with them.