Research hasn't defined the exact role stress plays in the development of heart disease.

However, elevated levels of cortisol and epinephrine appear to be the most significant factors in the development of heart disease associated with stress.

Chronic stress is hard on the heart because the fight-or-flight response remains activated.

The adrenal glands release the stress hormones adrenaline and cortisol.

The heart speeds up, blood vessels are constricted, and clotting factors in the blood are activated as preparation for a possible injury.

This response burdens the heart muscle and reduces the supply of blood to the coronary arteries.

Also stress may lead to unhealthy behaviors. For example, if you are under stress, you may overeat, you may exercise less, and you may be more likely to smoke or use alcohol excessively.