Adrenaline, or epinephrine, is one of the body's most important fight-or-flight stress hormones. It is secreted in the adrenal glands above the kidneys in response to frightening or threatening situations. Adrenaline binds to receptors on the heart and the smooth muscles of blood vessels, which gives rise to a quickening of the heartbeat, an increase in the force of heart contractions and increased respiration. Together with other stress hormones, such as cortisol and noradrenaline, adrenaline prepares the body for a successful escape from or elimination of the imposing threat by increasing energy and oxygen supplies to the muscles.
Stress
One of the prime causes of an adrenaline rush, or a sudden surge of adrenaline, is psychological and physiological stress. Stress-induced adrenaline rushes have far more devastating consequences than hitherto recognized, reports a Tel Aviv research team in the January 2007 issue of "Brain, Behavior and Immunity." The team studied cancer patients undergoing surgery and found that peaking levels of adrenaline before and during surgery due to physiological and psychological stress are the main trigger of the weakened immune system found in cancer patients who have undergone surgery. Tissue damage is only a minor factor in comparison, the researchers report.
Cardiomyopathy
Stress cardiomyopathy, or broken heart syndrome, is a sudden extreme surge of adrenaline in response to a negative emotional event, such as a traffic accident, armed robbery, the loss of a loved one, a divorce or a breakup. In cardiomyopathy, the extreme surge in adrenaline temporarily weakens or stunts the heart muscle, reports a John Hopkins research team in the February 2006 issue of "The New England Journal of Medicine." Examining 19 participants with stress cardiomyopathy, the researchers found that cardiomyopathy gives rise to symptoms nearly indistinguishable from symptoms of a heart attack, such as chest and neck pain, fluid in lungs, difficulties breathing and heart failure. Though the condition is reversible, it can be deadly, the researchers add.
Loneliness
Lonely people experience a mild to moderate adrenaline rush on a daily basis, according to a study published in the August 2007 issue of "Current Directions in Psychological Science." Even though lonely people, on average, have been subject to the same number of emotionally painful events, including death of relatives, loss of jobs, divorce and breakups, they are more likely to remember the details and negative tinting of the events than socially active people, the researchers report. These memories, which may not always be experienced at a conscious level, trigger surges in adrenaline and other stress hormones, which may lead to deterioration in overall health, the researchers report.
Heart Failure
During heart failure, the heart loses its ability to pump blood into the body's arteries. This sends a signal to the adrenal glands to produce more adrenaline to make the heart work harder. Adrenaline, however, is toxic to a failing heart. Fortunately, beta-blockers, a group of drugs that inhibits the heart's receptors for adrenaline, can prevent a toxic heart and halt the progression of heart failure, reports a Yale research team in the July 2004 issue of "Archives of Internal Medicine." The researchers analyzed data from nine clinical trials that compared patients with heart failure who were randomly given either beta-blockers or a placebo and found a 27 percent reduction in mortality in patients who received beta blockers.
References
- "Brain, Behavior and Immunity"; Immune Suppression While Awaiting Surgery and Following It: Dissociations Between Plasma Cytokine Levels, Their Induced Production and NK Cell Cytotoxicity; Keren Greenfeld et al.; January 2007
- "The New England Journal of Medicine"; Myocardial Stunning Due to Sudden Emotional Stress; Ilan S. Wittstein et al.; February 2005
- "Archives of Internal Medicine"; Adverse Effects of {beta}-Blocker Therapy for Patients With Heart Failure; Dennis T. Ko et al.; July 2004
- "Current Directions in Psychological Science"; Aging and Loneliness: Downhill Quickly?; Louise Hawkley and John Cacioppo; August 2007
