Stress is a measure of your mental and physical resistance to circumstances beyond your control. Stressors are threats, demands, or changes to which you attach special, significant importance, and with which you may struggle or feel uncertainty. 

 Stress is the leading cause of sudden death  especially in young healthy people with no evidence of coronary disease. But it can fell people at any age 

Stress causes deterioration in everything from your gums to your heart and can make you more susceptible to illnesses ranging from the common cold to cancer, according to a review essay in the Dec. 2007 issue of the Association for Psychological Science's magazine Observer.  

Stress also indirectly contributes to other lifestyle habits that create more free radicals.If stress causes you to lose sleep, eat junk food, drink too much alcohol, or smoke cigarettes to relax, these are contributing to your free radical load

Stress causes moderate to severe mental or physical pain for a huge number of people every year.  And through preventable stress-related lifestyle issues it leads directly to death for millions. 

Stress increases the size, activity level and number of neural connections in this part of your brain.This makes you more fearful, causing a vicious cycle of even more fear and stress. 

Stress can cause of death, actually stress is the first cause of disease like heart attack, high blood pressure and many more. Low level stress can raise the risk of fatal heart attacks and stroke by twenty per cent, scientists have warned. Research has found symptoms of anxiety or depression, known as psychological distress, increases mortality rates from several major causes. 

According to the American Psychological Association, chronic stress is linked to the six leading causes of death: heart disease, cancer, lung ailments, accidents, cirrhosis of the liver and suicide. And more than 75 percent of all physician office visits are for stress-related ailments and complaints.