Life events: a new year, job loss, new job, divorce, marriage, illness, new house, starting a new diet, death of a loved one. Unexpected or anticipated, good or bad, life events are certain to happen and to cause stress, and stress is a normal reaction to anything that changes your routine. The events that provoke stress are called stressors.

The human body responds to stressors by activating the nervous system and specific hormones. This response, called the stress response, is a natural reaction and when working properly, can enhance a person's ability to perform well under pressure or tackle an immediate pressure. It may even give you one of those "aha" moments. The nervous system returns to its normal state and is ready to respond again, when needed.

Some stressors are traumatic, like a disaster or accident. Others are ongoing or are compounded by multiple events, causing continued or severe pressure on the stress response. When this happens, the system is overwhelmed and has little time to recover. When the nervous system remains activated over extended periods, it pumps out extra stress hormones and wears out the body's reserves. That's when stress overload occurs, and that overload can hurt our bodies. There is virtually no part of the body that can't be affected by stress, in fact, some estimates attribute up to two-thirds of doctor visits to stress-related problems.

While physical, mental and behavioral changes vary among individuals, there is little doubt that the body's reactions to stress overload can weaken the body. Understanding stress, determining its source, how it affects you, and learning ways to manage it are essential to minimizing its harmful effects.