What are Alzheimer’s disease Causes??
Scientists declare that for most people, Alzheimer’s disease in patients is caused by a combination of genetic, lifestyle and environmental factors that influence the brain over time. Less than 5 percent of the time, Alzheimer’s is caused by specific genetic change that virtually guarantee a person will develop the disease. Although the Alzheimer’s disease Causes aren’t yet fully understood, its effect on the brain is clear. Alzheimer’s disease damages and kills brain cells. A brain affected by Alzheimer’s disease has many smaller number of cells and many fewer connections among surviving cells than does a healthy brain.As more and more brain cells die, Alzheimer’s leads to significant brain shrinkage. When doctors observe Alzheimer’s brain tissue under the microscope, they see two types of abnormalities that are considered hallmarks of the disease:
- Plaques. These clumps of a protein called beta-amyloid may damage and destroy brain cells in several ways, including interfering with cell-to-cell communication. Although the ultimate cause of brain-cell death in Alzheimer’s isn’t known, the collection of beta-amyloid on the outside of brain cells is a prime suspect.
- Tangles. Brain cells depend on an internal support and transport system to carry nutrients and other essential materials throughout their long extensions. This system requires the normal structure and functioning of a protein called tau.
Age:Increasing age is the greatest known risk factor for Alzheimer’s. Alzheimer’s disease is not a part of normal aging, but your risk increases greatly after you reach age 65. The rate of dementia doubles every decade after age 60.
Family history and genetics:Your risk of developing Alzheimer’s appears to be somewhat higher if a first-degree relative — your parent or sibling — has the disease. Scientists have identified rare changes (mutations) in three genes that virtually guarantee a person who inherits them will develop Alzheimer’s. But these mutations account for less than 5 percent of Alzheimer’s disease.
Down syndrome:Many people with Down syndrome develop Alzheimer’s disease. Signs and symptoms of Alzheimer’s tend to appear 10 to 20 years earlier in people with Down syndrome than they do for the general population. A gene contained in the extra chromosome that Alzheimer’s disease Causes Down syndrome significantly increases the risk of Alzheimer’s disease.
Sex:Women seem to be more likely than are men to develop Alzheimer’s disease, in part because they live longer.
Mild cognitive impairment:People with mild cognitive impairment (MCI) have memory problems or other symptoms of cognitive decline that are worse than might be expected for their age, but not severe enough to be diagnosed as dementia.