Table of Contents
Complications
In prehistoric times, the physical changes in response to stress were an essential adaptation for meeting natural threats. Even in the modern world, the stress response can be an asset for raising levels of performance during critical events, such as a sports activity, an important meeting, or in situations where there is actual danger or a crisis.
If stress becomes persistent and low-level, however, all parts of the body's stress apparatus (the brain, heart, lungs, blood vessels, and muscles) become chronically over-activated or under-activated. Such chronic stress may produce physical or psychological damage over time. Acute stress can also be harmful in certain situations, particularly in individuals with pre-existing heart conditions.
Psychological Effects of Stress
Studies suggest that the inability to adapt to stress is associated with the onset of depression or anxiety.
Some evidence suggests that the repeated release of stress hormones produces hyperactivity in the hypothalamic-pituitary-adrenal (HPA) system, and disrupts normal levels of serotonin, the brain chemical that is critical for feelings of well-being. Some people appear to be more at risk for an overactive HPA system under stress, including those with personality traits that cause perfectionism. On a more obvious level, stress reduces quality of life by affecting feelings of pleasure and accomplishment. In addition, relationships are often threatened in times of stress.
Heart Disease
The full impact of mental stress on heart disease is just coming to light, but the underlying mechanisms are not always clear. Stress can influence the activity of the heart when it activates the automatic nervous system, which affects many organs, including the heart. Such actions and others could negatively affect the heart in several ways:
- Sudden stress increases the pumping action and rate of the heart, while at the same time causing the arteries to constrict (narrow).
- The emotional effects of stress alter the heart rhythms, which could pose a risk for serious arrhythmias (rhythm abnormalities) in people with existing heart rhythm disturbances.
- Stress causes the blood to become stickier (possibly in preparation for potential injury).
- Stress appears to impair the clearance of fat molecules in the body.
- Stress that leads to depression appears to be associated with increased intima-medial thickness, a measure of the arteries that signifies worsening blood vessel disease.
- Stress causes the body to release inflammatory markers into the bloodstream. These markers may worsen heart disease or increase the risk of a heart attack or stroke.
- Studies have reported an association between stress and high blood pressure, which may be more pronounced in men than in women. According to some evidence, people who regularly experience sudden spikes in blood pressure (caused by mental stress) may, over time, develop injuries to the inner lining of their blood vessels.
Evidence is still needed to confirm any clear-cut relationship between stress and heart disease. However, research has linked stress to heart disease in men, particularly in work situations where they lack control. The association between stress and heart problems in women is weaker, and there is some evidence that the ways in which women cope with stress may be more heart-protective.
A condition called stress cardiomyopathy (or Takotsubo cardiomyopathy) is widely recognized. In this disease, intense emotional or physical stress causes severe but reversible heart dysfunction. The patient experiences chest pain, and EKGs and echocardiograms indicate a heart attack, but further tests show no underlying obstructive coronary artery disease.
Psychological stress is also recognized as a possible cause of acute coronary syndrome (ACS), a collection of symptoms that indicate a heart attack or approaching heart attack. High levels of psychological stress are associated with harmful changes to the blood. Research suggests that stress has the potential to trigger ACS, particularly in patients with heart disease. Studies also suggest that the risk is greatest immediately after the stressful incident, rather than during it.
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Review Date: 10/14/2010
Reviewed By: Reviewed by: Harvey Simon, MD, Editor-in-Chief, Associate Professor
of Medicine, Harvard Medical School; Physician, Massachusetts
General Hospital. Also reviewed by David Zieve, MD, MHA, Medical
Director, A.D.A.M., Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
