Introduction: Killer Stress (03:11)

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A patient suffers chest pain after having lost his job. Stress increases blood pressure and can contribute to cancer, sudden death from heart attack, and bacterial infection. This program looks at causes of and ways to protect against the silent killer.

Physiological Stress Response (04:04)

Examiners place a subject under psychological stress. The amygdala responds to fear and anxiety by prompting the adrenal glands to release stress hormone, increasing the heart rate and clotting. The autonomic nervous system constricts blood vessels, raising blood pressure.

Stress Response and Human Evolution (02:08)

Rapid movement and quicker blood clotting mechanisms saved hunter-gatherers, but we are no longer threatened by wild animals. Our bodies still respond automatically to fear—potentially causing harm when triggered by pressures of modern life.

Heart Attack and Stroke Cases (03:49)

A man in his 50s suffers a myocardial infarction, a condition that can cause sudden cardiopulmonary arrest. A 60 year old woman suffers a cerebral hemorrhage. She had been stressed at work and then had a family death.

Multiple Stressor Response (04:23)

Stress hormones inundate the body, increasing heart rate and blood pressure and risking artery rupture. Overexcited nerves constrict heart blood vessels. Blood flow decreases in the heart muscle among heart attack survivors. This combination can cause sudden cardiac death.

Stress Susceptibility (01:23)

A study of heart attack survivors revealed that stress response varies according to sex and age. Men over 50 and women under 50 experienced more restricted blood flow inside the heart—suggesting younger women are more vulnerable to stress-related pathology.

Environmental and Lifestyle Stress (03:12)

A study showed heart disease and stroke incidence spiked after the East Japan earthquake, and again after an aftershock. London researchers followed 4,000 public servants over eight years. They found that increased stress hormone accumulation increases heart disease risk.

How Killer Stress Causes Cancer (03:09)

Researchers are investigating how stress accelerates cancer development. Stress hormone activates the ATF3 gene in immune cells, causing them to stop attacking cancer cells. This decreases breast cancer survival rates.

Stress and Bacteria (04:17)

Researchers found abnormal bacteria in blood vessels of arterial sclerosis patients. Oral bacteria enter the blood stream through bleeding gums. Combined with stress hormone that isolates iron, microorganisms erode the vessel wall—increasing risk of rupture and major bleeding.

Dental Bacteria and Stroke (01:16)

Researchers collected the saliva of stroke patients to analyze their oral bacteria. They identified certain strains likely to cause stroke. Dentistry may one day reduce cerebral hemorrhage incidence.

Stress and Common Illnesses (03:27)

In the 1980s, researchers exposed 394 test subjects with varying stress levels to a cold virus; those with higher stress had weakened immune systems. Stress can increase incidence of rash, allergy, gastritis, gastric ulcer, deep vein thrombosis, diabetes, and depression.

Stress and Modern Lifestyle (03:17)

Amygdala sensitivity is higher among urban residents and lower among villagers. The Life Event Stress Check evaluates risk of developing a life threatening disease. Both positive and negative events stimulate the amygdala.

Reducing Stress (03:35)

Taking a break from stressors, seeking social support, and exercising can reduce stress. Researchers found greater autonomic nervous system activity in myocardial infarction patients. A six month exercise regime lowered it to normal levels.

Exercise and Brain Structure (03:57)

A study found medulla neuron branch points were 50% fewer in physically active rats than those in sedentary rats—preventing an overreaction to stress in the autonomic nervous system and slowing stress hormone release in the adrenal glands.

Increasing Physical Activity (03:01)

University of Western Ontario study participants walked three times a week to reduce stress levels. Therapists use activity to recondition the autonomic nervous system. A MI patient walks to improve his condition and remain positive. Hear a killer stress summary.

Credits: Killer Stress—The Causes: Medical Revolution (00:27)

Credits: Killer Stress—The Causes: Medical Revolution