(HealthDay News) - Bruises occur when small blood vessels break and bleed beneath the skin.

If you bruise easily, here are possible reasons why, courtesy of the University of Cincinnati's Net Wellness program:

• If you take blood-thinning medications, such as heparin or warfarin; over-the-counter medications such as aspirin or ibuprofen; or certain herbal supplements.
• If you drink too much alcohol.
• If you have a vitamin C deficiency.
• If you have certain conditions of the liver or kidneys.
• If you have certain bleeding disorders, including hemophilia or von Willebrand's disease.
• Normal aging.