How to Know if a Bruise Is Serious. Bruising commonly appear after falls or when trauma or pressure has been focused on a specific portion of your body. Usually bruises are relatively harmless. However, it's important to know when a bruise is a result of a more serious medical condition and needs a doctor's attention.
Determine how long the bruise has been visible. A normal bruise will change from red to purple to green to yellowish brown over 2 to 3 weeks. If a bruise lasts longer than this, it may be more serious.
Decide if the bruise is growing and becoming firm rather than getting smaller. Sometimes the body reacts to trauma by walling off the blood, causing a hematoma. This bruise may need to be drained by your doctor.
Check to see if the bruised area becomes more tender and firm. This could indicate a condition called ossification. Calcium deposits have formed in the injured area and can only be diagnosed by x-ray.
Look at the location and type of bruises that appear without an injury. Bruises around the navel may indicate bleeding in the abdomen. Small red dots beneath the skin, especially on the legs, are called Petechia and can signify other serious health conditions. Bruises that appear behind the ear may indicate a skull fracture. If any of these symptoms are present, seek the attention of your health care provider.
If you are unsure about the cause of any bruise and are concerned about its size and appearance, see your doctor immediately.