What causes that dark, unsightly mark on a limb known as a bruise? Unable to remember bumping into anything, an older adult may be baffled about how a new bruise happened. It’s common to experience easy bruising with increasing age, because blood vessels become more fragile with age.

Bruises result when trauma or a blow to the body damages or ruptures tiny blood vessels under the skin. Not only are the elderly more prone to bruising, less force is required to cause a bruise. And with greater impact, deeper bruises of the muscles or bone can happen, which take longer to heal.

According to A Place for Mom, the medical term for a bruise is a contusion. What happens is blood leaks out of the vessels and initially appears as a bright or dark red, purple or black mark. Eventually the body reabsorbs the blood, and the mark disappears. If a bruise increases in size and becomes swollen and hard, it may be a hematoma, a localized collection of blood which becomes clotted or partially clotted.

Some people – especially women – are more prone to bruising than are others. In fact, several factors may contribute to increased bruising, including (Mayo Clinic):

• Aging capillaries – Over time, the tissues supporting these vessels weaken, and capillary walls become more fragile and prone to rupture.
• Thinning skin – With age, skin becomes thinner and loses some of the protective fatty layer that helps cushion blood vessels against injury. Excessive exposure to the sun accelerates the aging process in the skin.

Generally, the harder the blow, the larger the bruise. However, if a person bruises easily, a minor bump – one they may not even notice – can result in substantial discoloration. Arms and legs are typical locations for bruises.

Blood-thinning drugs such as aspirin and warfarin (Coumadin) or medications such as clopidogrel (Plavix) reduce the blood’s ability to clot. Because of this, bleeding from capillary damage that would normally stop quickly may take longer to stop, allowing enough blood to leak out to cause a bruise.

In addition, certain dietary supplements such as fish oil and ginkgo also may increase bruising, because these supplements have a blood-thinning effect. Make certain the doctor knows about any supplements.

Bruise prevention

Below are some steps to take to prevent bruising from falls and collisions:

• Hold the handrails on stairways.
• Don’t stand on a chair to get to something.
• Clear floors where you walk.
• Mount grab bars near toilets, tubs and showers.
• Place non-skid mats, strips, or carpet on all surfaces that may get wet.
• Put night lights and light switches close to your bed.
• Tack down all carpets and area rugs.
• Always close cabinet doors and drawers so you won’t run into them.
• Be especially careful around pets.