Stress is the medical term for a person’s physical and emotional response to change. It affects individuals of all ages.

Although most people tend to view all types of stress as bad, stress can be either positive or negative. Sources of positive stress include having a new baby and starting an exciting new job. Sources of negative stress include divorce, unemployment and legal battles. It may take only a short time to adjust to the change (acute stress), or the adjustment may be more gradual (chronic stress).

Acute stress is an immediate reaction to a change that is perceived as threatening (stressor). Sources of acute stress include suddenly being cut off by a car in traffic, and hearing a loud, unexpected noise. In addition to creating feelings such as fear and/or anxiety in the person, stress can also set off the body’s alarm system, triggering a “fight or flight” response. This short-term response prepares the body to either fight or flee from a perceived threat.

If all stressors were acute, people would simply respond to an immediate threat, and then their body’s systems would return to normal. However, people encounter many changes to which it is more difficult to respond, such as daily job stress, unrelenting financial pressures and dysfunctional, long-term relationships. The longer people go without either changing or adapting to these changes, the longer they will experience stress. The type of stress that people experience for a long period of time is called chronic stress.

Because chronic stress results from changes that are not addressed, this lack of action leaves the body in a state of heightened awareness or tension. Sooner or later, the energy drain on the system will cause the body to fall behind in the self-repair and maintenance necessary for good health. The unrelenting wear and tear brought about by stress hormones can affect the following body systems:

• Nervous system. Hormones related to chronic stress produce persistent feelings of helplessness, anxiety and impending doom. Oversensitivity to chronic stress has been associated with major depression. This may be because individuals with depression find it more difficult to adapt to the negative effects of the hormone cortisol, which is responsible for supplying the body with the energy necessary to respond to a stressful situation. Excess levels of cortisol can also lead to sleep disturbances (e.g., insomnia) and decreased sex drive.
  
  
• Digestive system. Chronic stress is associated with a number of digestive problems, including stomachache, heartburn, diarrhea, irritated ulcers, colitis (inflamed colon) and irritable bowel syndrome (IBS). Stress triggers these digestive problems in a number of ways. Stress hormones may delay the release of stomach acid and increase the amount of time it takes to empty the stomach.  They also stimulate the colon, causing its contents to pass more quickly. Excess levels of the hormone cortisol can also lead to either increased appetite or appetite loss.
  
  
• Immune system. Chronic stress can suppress the immune system, resulting in more upper respiratory infections and other infectious diseases as well as slowed wound healing. Individuals with compromised immune systems (e.g., due to disease) are even more vulnerable to the effects of stress. For instance, stress can affect blood sugar levels in patients with diabetes, and may trigger outbreaks in individuals with herpes simplex virus.
  
  Conversely, stress can also cause the immune system to become overactive in some instances. This increases a person’s risk of developing an autoimmune disease (in which the immune system attacks its own cells). In addition, stress can worsen the symptoms of a pre-existing autoimmune disease. For example, stress can trigger symptom flare-ups in individuals with lupus or multiple sclerosis (MS).
  
  
• Cardiovascular system. Excess amounts of cortisol can raise a patient’s heart rate and increase their blood pressure, cholesterol and triglyceride levels, placing them at increased risk for heart attack and stroke. Elevated cortisol levels may also lead to excess body fat in the abdominal region, a risk factor of both diabetes and heart disease. In addition, stress can induce angina, which is a risk factor of heart attack.
  
  
• Muscular system. Stress has been associated with muscles spasms and aching in the jaw, neck, back and shoulders.
  
  
• Other systems. Stress is also associated with the following:
  
• • Elevated blood pressure
  • Skin conditions (e.g., acne, hives)
  • Asthma attacks
  • Arthritis flare-ups
  • Increased chronic pain