Fatigue and sleepiness do not mean the same thing, although sleepiness can occur because of fatigue. Fatigue best describes a tiredness that pervades mood, muscles and psychological outlook. "Dorland's Illustrated Medical Dictionary, 31st ed.," further adds, "loss of power or capacity to respond to stimulus." A number of triggers cause extreme fatigue, but all fall into one of three categories: lifestyle, disease and psychological.
External causes
Daily stresses afflict most people in the modern world. However, some live at the extreme end of stress. The overachiever who makes unreasonable demands on himself and then runs out of steam fits this category. Society demands a lot from you. You may have mortgages, car payments, children's colleges, credit card payments and much more. Then there are those job promotions to land, the in-laws to impress and children to satisfy.
Personal causes
Another victim of fatigue, the insomniac, has no time for the rejuvenation of cells and spirit. Even a newborn's middle of the night feedings can interrupt the restful sleep needed by the parents. Also, the athlete who pushes his body to its limits day after day does not allow his muscles to regenerate properly. These dire situations, though part of life, don't change the fact that every body has limitations.
Disease as a cause
Severe fatigue that does not emanate from lifestyle can have its roots in an underlying disease. According to a Mayo Clinic posting in 2010, thyroid disorders, heart disease and diabetes cause the dragged-out feeling of fatigue. Chronic obstructive pulmonary disease, COPD, forces the body to strain for every breath, which causes exhaustion. Cancer also robs the body of the energy it once had. Medical treatments such as chemotherapy, radiation and certain high-powered drugs cause fatigue, tiredness and sleepiness.
Chronic conditions
The aches and pains of arthritis tire a body out. In fact, anyone with chronic pain suffers from the fatigue that comes from living with it every day or losing sleep because of it. The Mayo Clinic states that in years past, symptoms and causes of fatigue eluded medical measures, but today we recognize a condition called chronic fatigue syndrome, which has both psychological and physical components. Only a doctor can make this diagnosis.
Psychological causes
The mind has tremendous power over the body. Depression, especially over loss of a loved one, erodes a person's energy. She may prefer sleep over participation in daily life. The person who finds himself carrying everyone else's burdens on his shoulders learn quickly that the body can only take so much before it shuts down. Those who walk around in a constant state of irritability find themselves exhausted from the negative use of their energy.
References
- Dorland's Illustrated Medical Dictionary 31st. ed.; Saunders Elsevier, pub.; 2007
- The Mayo Clinic: Fatigue; 2010
