Tiredness brought on by overwork or lack of sleep is the most common kind of fatigue, and through the ages caffeine--in its many forms--has been the treatment of choice. Coffee is, in fact, the strongest natural form of caffeine. But coffee is addictive: drinking more than three cups a day can cause problems, including jangled nerves and diarrhea.

Other sources of caffeine include tea, colas (and sometimes other soft drinks), cocoa (a stimulant for some people), the South American beverage yerba mate, and many over-the-counter drugs. Although tea has significantly less caffeine than coffee, it contains more of a related compound called theophylline, which, in pure form, is used to treat asthma. Like caffeine, it can cause insomnia, nervousness, and increased heart rate.

When fatigue is caused by stress, folk practitioners have prescribed a variety of herbal relaxants, including lavender and valerian. Stress can cause you to lose sleep at night, leading to deep exhaustion during the day.

Herbal Remedies

Black tea A cup of black tea contains about 30 mg of caffeine. Doses of roughly 60 mg--the equivalent of 2 cups--act as a stimulant to increase the activity of the central nervous system. To prepare, pour 1 cup boiling water over 11/2 teaspoons black tea leaves. Let steep for 5 minutes, then strain and drink.

Valerian A sleeping aid for more than 2,000 years, valerian is helpful in treating stress-induced fatigue. Use 1 cup boiling water to 1/2 to 1 teaspoon minced fresh roots to make a bedtime tea. Or mix a few drops of valerian extract or tincture into a glass of warm water. Use for longer than two weeks is not recommended.