Stress Illnesses Research Starter
A wide variety of human illnesses and disorders have been associated with stress. Heart disease, certain cancers, stroke, mental illness, allergies, accidents, asthma, chronic fatigue, chronic pain, and suicide are among the many illnesses and disorders that are considered by scientists to be stress-related illnesses. Six of the top ten leading causes of death in the United States, including heart disease, cancer, respiratory diseases, unintentional injuries (accidents), stroke, and suicide, are linked to chronic stress. Some studies have estimated that the majority of all visits to primary care physicians are due to stress-related complaints, such as headaches, muscle tension, peptic ulcers, chronic pain, lowered immune system function, and flare-ups of rheumatoid arthritis and systemic lupus erythematosus.
There still is some debate concerning the causal relationship between stress and illness, despite overwhelming scientific evidence demonstrating bodily responses to stressful situations. Abnormal nerve hyperactivity and prolonged, abnormal secretions of gene-regulatory hormones from various endocrine glands disrupt the balanced homeostasis of many different body systems. Immune system reduction often occurs due to chronic stress, thereby making a stressed individual more susceptible to contracting infectious bacterial and viral diseases.
Physiological Stress Responses Research Starter
Stress is, therefore, a biochemical response to danger that occurs within animals. The nervous system detects danger from internal or external stimuli, usually external stimuli, such as predators, competitors, or life-threatening events. Increased electrical conductivity along millions of nerve cells targets various tissues to prepare the body for maximum physical activity. Among the tissues affected will be the skeletal muscles, the heart muscle, the hormone-secreting glands of the endocrine system, the immune system, the stomach, and blood vessels. Under nerve-activated stress, skeletal muscles will be poised for contraction. The heart will beat faster, thereby distributing more blood and nutrients to body cells, in the process accelerating the breathing rate to distribute more oxygen. Blood vessels will constrict. The stomach and other intestinal organs will decrease their activity, including a decreased production of mucus that protects against acid.
Heightened nerve activity also will trigger the production of various hormones from the immune system, specifically hormones that influence bodily metabolism, such as thyroxine and epinephrine (adrenaline). These hormones target body tissue cells to prepare the body for increased output in the face of danger. Massive production of epinephrine will trigger maximum physical readiness and extraordinary muscular output, a phenomenon often referred to as the fight-or-flight response.
