Effects of Stress on Brain

Many psychological studies reveal that a significant number of medical consultations occur due to psychological problems and a fair number of them are a result of acute or chronic stress.

Stress is a normal reaction of our body. It is a process that is activated when we perceive a threat and involves an appraisal and attempt to cope with the physical, emotional and psychological situation.

It is an excellent mechanism that evolved in mammals years ago. The evolution helped man to increase the chances of survival in life threatening situations. The reaction of the body in such emergency situations is to cease optimal functioning of all non-essential body systems. The entire attention is diverted to the muscles and the brain so that the emergency situation can be tackled effectively.

Encounters with muggers in a dark alley, a car accident about to happen or loss of a loved one are universal examples that elicit a stress response.

Basically, there are three organs that are involved during a stress response. One is located inside the brain (the hypothalamus), the second at the base of the brain (pituitary gland) and the third near your kidneys (adrenal glands). All three work in tandem and are involved in a complex system known as hypothalamo-pituitray-adrenal (HPA) axis.

Once your brain has determined that danger exists, it signals the adrenal glands through nerve signals that are sent through the spinal cord to release adrenaline. Once the adrenaline is released, it stimulates autonomic nerve action and among other things, elevates blood pressure, increases heart rate and increases blood pressure.

At the same time, the hypothalamus in the brain sends signals to the pituitary gland, the master gland of the endocrine system, to release factors that travel through the blood and stimulate the adrenal glands to release cortisol, commonly known as the stress hormone. Cortisol is important for keeping blood sugar and blood pressure up so that we are able to fight or flee danger.

The changes that occur in the brain and body during a stress reaction are normal and harmless as long as the threat lasts for a short period of time and the body reverts to its normal state. However, the high alert state can be extremely harmful if it continues for a long period of time. High cortisol levels in the blood can weaken the immune system and kill brain cells. Researchers have found that prolonged stress can actually shrink certain areas of the brain, especially the hippocampus area, which plays an important role in long term memory.

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