Alzheimer's

**// Alzheimer's disease //**

 * The original criteria for Alzheimer's disease, or AD, defined the disease in a single stage and assumed people who didn't have symptoms did not have the disease. This definition only addressed later stages of the disease. **

**There are now** three stages **to AD**

 * **Preclinical Alzheimer's disease**
 * **Mild cognitive impairment (MCI)**
 * **Dementia because of Alzheimer's**

// Causes and risk factors //
**There are two types of AD, early onset and late onset.**
 * ** As you get older, your risk of developing AD goes up. **
 * ** Having a close blood relative who developed AD. **
 * ** Having certain combination of genes for proteins that appear to be abnormal. **
 * ** In early onset AD, symptoms first appear before age 60. Early onset AD is much less common than late onset but tends to progress rapidly. Early onset disease can run in families. **
 * ** Late onset AD, the most common form of the disease, develops in people age 60 and older. Late onset AD may run in some families, but the role of genes is less clear. **

**The cause of AD is not entirely known, but is thought to include both //genetic// and //environmental// factors. A diagnosis of AD is made when certain symptoms are present, and by making sure other causes of dementia are not present. The only way to know for certain that someone has AD is to examine a sample of their brain tissue after death, the following will happen.**
 * ** Neurofibrillary tangles (twisted fragments of protein within nerve cells that clog up the cell) **
 * ** Neuritic plaques (abnormal clusters of dead and dying nerve cells, other brain cells, and protein) **
 * ** Senile plaques (areas where products of dying nerve cells have accumulated around protein). **
 * When nerve cells are destroyed, there is a decrease in the chemicals that help nerve cells send messages to one another. As a result, areas of the brain that normally work together become disconnected. **

//** Symptoms **//

 * Dementia symptoms include difficulty with many areas of mental function, including: **
 * ** Language **
 * ** Memory **
 * ** Perception **
 * ** Emotional behavior or personality **
 * ** Cognitive skills **
 * ** Forgetting details about current events **
 * ** Forgetting events in your own life history or losing awareness of who you are **
 * ** Change in sleep patterns, often waking up at night **
 * ** Difficulty reading or writing **
 * ** Poor judgment and loss of ability to recognize danger **
 * ** Using the wrong word, mispronouncing words, speaking in confusing sentences **
 * ** Withdrawing from social contact **

**In the U.S., 5.4 million people have an Alzheimer's diagnosis. By 2050, that number is expected to more than //triple.//**

**Resources:** Alzheimer's Association National Institute on Aging Caring.com -- Simplifying caregiving, supporting caregivers

"Alzheimers." //What is Alzheimers//. Alzheimers Association, 19 Apr 2011. Web. 19 Apr 2011. .
 * Work Cited:**