It's Monday morning after a weekend of outdoor fun. As you're getting ready for work, you notice several small bruises on your right leg. Not recalling any bumps that may have caused them, you wonder where they came from.

"Most bruises, or contusions, are harmless natural reactions to minor trauma," says Dr. Richard Dobyns, associate professor of family practice at the University of Iowa College of Medicine. "Everyone gets bruises, it's just that some people bruise easier than others." Those bruises on the front of your leg occurred when a blow to the skin caused tiny blood vessels to break. This caused blood to seep into surrounding tissue. Women bruise easier than men because their higher ratio of body fat makes blood vessels less elastic and susceptible to breakage. Older or overweight people also bruise easier due to the decreased elasticity of their blood vessels.

Bruises may appear worse if you are taking aspirin, ibuprofen, or antibiotics. Very rarely, bruising may indicate liver disease or a cancer of the blood. "Out of those who bruise, only 20 percent pose concern," Dobyns says.

If you seem to bruise often, increase your intake of green vegetables. Vitamin K, which speeds healing of bruises, is found in such vegetables as broccoli, spinach, and lettuce. Reducing fat in your diet and exercising regularly will keep blood vessels healthy.

Although the application of a cold wet cloth to the injured area may keep the bruise from becoming too livid, the bruise should disappear by itself in 10 to 14 days. During the normal course of events, a bruise goes through four phases before being absorbed by the body. At first, the bruise will appear bluish-red, then red-blue, before finally fading to green-yellow and brown.

If a bruise does not fade, or you have obvious bruising that is not the result of trauma, see your physician.