A bruise, also called a contusion (pronounced: kun-TOO-zhen), happens when a part of the body is injured and blood from the damaged capillaries (small blood vessels) leaks out. With no place to go, the blood gets trapped under the skin, forming a red or purplish mark that's tender when you touch it — a bruise.
Bruises can happen for many reasons, but most are the result of bumping into things — or having things bump into you.
Anyone can get a bruise. Some people bruise easily, while others don't. Why? Bruising depends on several things, such as:
how tough the skin tissue is
whether someone has certain diseases or conditions
whether a person's taking certain medicines
Also, blood vessels tend to become fragile as people get older, which is why elderly people tend to bruise more easily.
How Long Do Bruises Last?
Bruises usually fade away in about 2 weeks. Over that time, the bruise changes color as the body breaks down and reabsorbs the blood. The color of the bruise can give you an idea how old it is:
When a bruise first happens, it's kind of red as the blood appears under the skin.
Within 1–2 days, the hemoglobin (an iron-containing substance that carries oxygen) in the blood changes and the bruise turns bluish-purple or even black.
After 5–10 days, the bruise looks green or yellow.
Then, after 10–14 days, it turns yellow-brown or light brown.
Finally, the bruise fades away.
How Can I Help Myself Feel Better?
It takes time for bruises to get better, but there are a few things you can do to feel better during healing:
Apply a cold compress. As soon as you get a bump to the body, wrap a towel around a cold pack, bag of ice, or bag of frozen vegetables and place it on the injury. This can help keep the amount of bruising and swelling small by slowing the blood flow to the injured spot. Apply cold to the bruise for 15–20 minutes 3–4 times a day for a day or two after the bruise first appears
Raise the bruised area. To reduce swelling and bruising, raise the bruised area above the level of your heart. To do this, rest and prop the bruised area up on pillows, if possible.
Pain medicine might help. Try acetaminophen for pain, if needed.
Wrap the bruise. If the bruise is swollen, it may help if you wrap it loosely with an elastic bandage to give some support.
After 2 days, warmth may aid healing. A heating pad or warm washcloth wrapped in a towel can help some bruises heal. Even a warm bath can soothe sore areas. Warmth brings more blood flow to an area of the body, which can help as the body tries to heal the injury. Talk to your doctor to make sure heat is OK for your injury and definitely don’t use heat in the first 48 hours of an injury because that can make the bruising bigger.
When Should I Call the Doctor?
Minor bruises are easily treated, but it's probably best to talk to a doctor if:
A bruise isn't improving after 2 weeks.
You bruise often or seem to get bruises for no clear reason.
Your bruise is swollen and very painful.
You can't move a joint or you think you may have a broken bone.
The bruise is near your eye and you have trouble moving your eyes or seeing.
Can Bruises Be Prevented?
Bruises are kind of hard to avoid completely. But if you're playing sports, riding your bike, inline skating, or doing anything where you might bump, crash, or smash into something, it's smart to wear protective gear like pads, shin guards, and helmets. Taking just a few extra seconds to put on that gear might save you from a couple of weeks of aches and pains.