Scraped knees and little legs marked with bruises are a classic part of childhood — the marks of adventure as kids gain confidence on their feet, take tumbles on the playground and explore their surroundings with a few bumps along the way. Bruises are expected, and while most are harmless, some can raise questions and concerns for parents. Kelly Maloney, MD, pediatric hematology and oncology specialist at Children's Hospital Colorado, answers the most frequently asked questions about bruises: Why they happen, how to treat them and when to seek additional medical attention from your child’s doctor.

What are bruises and why do they occur?

A bruise occurs when small blood vessels under the skin break due to impact or trauma, such as a child bumping their leg into furniture or falling off a bike. This causes discoloration on the skin that can range from red to purple or blue, and then yellow as it heals. Bruises can vary in size and may be sore when you touch them. They typically fade over time as the body reabsorbs the blood.

How long does it take a bruise to heal?

Bruises typically heal within three to five days, but some bruises can take longer to heal than others. Within this time, bruises should begin fading or possibly turning yellow and should not be accompanied by any additional symptoms, such as small red bumps. There are no long-term health impacts or concerns with having multiple childhood bruises.

Can I do anything to help a bruise heal?

Unfortunately, there is nothing you can do to help a bruise heal. An ice pack on the injury can help ease some of the pain or swelling.

Do some people bruise more easily than others?

Yes, some people might have more fragility to their blood vessels causing them to bruise easier than others. Kids don’t necessarily bruise easier than adults, but as they’re much more active and sometimes clumsier than adults, they may get bruises more often.

Is there anything I can do to prevent bruising?

For the most part, bruises are just a part of childhood and can’t be prevented. When your child is playing outside like riding a bike or skateboard, you can encourage them to wear knee pads, elbow pads and a helmet to avoid bruises if they fall.

When should I be worried about a bruise, and when should I see a doctor for bruising?

Reoccurring bruises in uncommon places can sometimes be concerning.

“So, if your child has a single bruise on their back, they probably bumped their back on a corner or something like that,” Dr. Maloney says. “If they continue to have a bruise in an odd place that keeps reoccurring without a break — so there's never a time when there isn't a bruise — that could signal something more.”

Dr. Maloney also notes other symptoms that could indicate you should connect with your child’s pediatrician:

• Bruises that do not heal
• Reoccurring bruises without a good explanation
• Bruises that are accompanied by other symptoms such as fever or persistent tiredness
• Consistent bruises combined with a family history of bleeding disorders
• Bruises accompanied by small red dots 
• Bruises along with sudden, frequent nose bleeds (if this is unusual for your child)

In rare instances, excessive or serious bruising could be a sign of anemia, a vitamin deficiency, a blood clotting disorder or even certain types of cancer. But luckily, most bruises are just a sign of a happy and active childhood.