Everyone has said it at least once in their lives, “It’s just a bruise!” While most people assume bruises aren’t serious, the truth is that a bruise can result in dangerous complications.

After you’re in a car crash, some bruising is likely. You may have bruising from the seat belt, impacts to your neck, head or back, or other bruises. If that’s all that you think is wrong, you might pass on going to the hospital, but that’s not a good idea. Your bruising could be more serious than you think.

What is a bruise?

Bruising takes place when the vessels under the skin tear, rip or are punctured. Most of the time, these are small areas of damage from bumping into something or falling. As the blood enters the tissues around the blood vessels, the black-and-blue bruising appears.

You’re likely familiar with minor bruises. They often start black and blue and turn a number of colors before eventually healing completely. Most of the time, they’re gone within four weeks.

It’s a hematoma: Is that still just a bruise?

A hematoma is slightly different than a bruise despite being in the same medical category. A hematoma forms when blood pools under the skin and forces it to raise outward. Bruises generally do not have a firm lump. Hematomas, like bruises, don’t usually mean anything bad and aren’t serious in most cases.

When is bruising serious?

Bruising is serious when you already have bleeding problems or a low platelet count. Severe bruises over a large portion of the body may be dangerous, too. They can be a sign of internal bleeding. Blood clots can also develop from severe bruising, but they are not in the circulatory system and often do not pose a risk to you. In some cases, blood clots do need surgical removal.

After an accident, it’s important to seek medical help. Bruising that spreads or continues to grow can be a sign of life-threatening blood disorders or internal injuries.

What’s the worst bruise you ever had?