Stress Types

Acute stress

When you are faced with an immediate threat or stressful situation—such as narrowly avoiding an automobile crash or having an intense argument with a coworker—your body responds immediately to the threat by releasing chemicals that make it tense, alert, and ready for action. This is known as the stress response or the fight-or-flight response. Your body stays alert until your mind tells you that the situation has passed. Then your brain signals an "all clear" to your body, which stops producing the chemicals that caused the physical reaction and you gradually return to normal. The chemicals take 30 to 60 minutes to leave your system, so if you become stressed again within that time, your body won't recover between the two stressful events.

Acute stress can cause problems when your body doesn't fully recover from a stress reaction. This can happen for different reasons.
Your brain may fail to give the "all clear" signal, for reasons we don't yet understand. You may find yourself in so many stressful situations during the day that you are spending most of your time stressed, even though your body may return to normal between each stressful period.

Tension may be the first result of stress that you recognize and is an early sign that you might not be recovering from acute stress. Tense muscles are tight and feel "hard" to the touch. A tense mind makes you feel jumpy, irritable, and unable to concentrate. This could be your signal to do something about stress, both for your immediate comfort and to prevent the long-term effects of stress.

Acute stress generally is not very harmful, as long as it doesn't happen too often and your body has a chance to return to normal. However, it can trigger an abnormal heartbeat (arrhythmia) and even a heart attack in those with heart disease.

Chronic Stress

Chronic stress can be the result of many instances of acute stress or a life condition, such as a difficult job situation or chronic disease. In people with higher levels of chronic stress, the stress response stays on longer, contributing to their physical stress. Over time, chronic stress affects the cardiovascular system, the nervous system, and the immune system. For example, chronic stress can lead to high blood pressure and make you susceptible to infection and can affect many diseases, such as depression, heart disease, and asthma. Chronic stress may also result in memory loss.

More specifically, over time, long-term (chronic) effects of stress can have an effect on:
Cardiovascular disease: Stress can lead to high blood pressure, abnormal heartbeat (arrhythmia), problems with blood clotting, and hardening of the arteries (atherosclerosis). It also affects coronary artery disease, heart attack and heart failure.

Muscle pain: People with stress often have neck, shoulder, and low back pain. This may be due to constant tension in the muscle because of stress. Stress also affects rheumatoid arthritis.

Stomach and intestinal problems: Stress may be a factor in gastro esophageal reflux disease, peptic ulcer, and irritable bowel syndrome.

Reproductive organs: Stress can result in painful menstrual periods, decreased fertility, and erectile dysfunction.

The lungs: Stress can make symptoms of asthma and chronic obstructive pulmonary disease worse.

The immune system: Stress changes the immune system. The body becomes more vulnerable to many illnesses, from colds and minor infections to major diseases such as cancer.

Stress also plays a role in depression and diabetes.

Excerpt from yahoo.health.com

  
With following references:

• Seymour DJ, Black K (2002). Stress in primary care patients. In FV DeGruy III et al., eds., 20 Common Problems in Behavioral Health, pp. 65–87. New York: McGraw-Hill.
• Kaplan HI, et al., eds. (1994). Psychological factors affecting medical condition (psychosomatic disorders). In Kaplan and Sadock's Synopsis of Psychiatry, 7th ed., pp. 752–770. Baltimore: Williams and Williams.