There are a couple of things that you can do to prevent or minimize bruising after an injury. First, try a cold compress. Put ice in a plastic bag, wrap the bag in a towel (applying the ice directly to the skin can cause frostbite ), and place it on the injured area. Commercial ice packs are also available, but a bag of frozen peas makes an excellent substitute. It molds to the shape of the injured area and can then be re-frozen and used again (but don't eat them!). The cold reduces the blood flow to the area and therefore limits bleeding into the skin and reduces the size of the bruise. The cold also decreases the inflammation in the area of the injury and limits swelling in this way as well. If possible, elevate the area above the level of the heart. The lower an extremity is below the heart, the more blood will flow to the area and increase the bleeding and swelling.
Some people, especially women, are more prone to bruising than others, so one possible explanation may be that you are less likely to notice the injury that triggered the bruising. Moreover, as people grow older and continue to expose themselves to the damaging effects of the sun, the skin becomes more susceptible to bruising. With time, the skin thins, losing some of its fatty layer that cushions blood vessels against damage. Also, capillary walls become more fragile, and tissues that support blood vessels weaken as people age. So, the bumps — especially to the arms and legs — that once went unnoticed may now, as bruises, be hard to miss.