An intramuscular hematoma is a localized collection of blood within a muscle, typically resulting from some form of injury or trauma. This condition involves bleeding from blood vessels that then pools and often clots inside the muscle tissue itself. It is distinct from a superficial bruise, which involves bleeding closer to the skin’s surface.
What It Is
An intramuscular hematoma is a contained accumulation of clotted or partially clotted blood within a muscle, often contained by its fascia, the fibrous tissue that encases muscles. This containment by the muscle fascia differentiates it from a regular bruise, where blood can spread more widely under the skin. The blood becomes trapped, leading to localized swelling. These hematomas commonly develop in larger muscle groups, such as those found in the thigh, calf, or arm, although they can occur in any muscle in the body.
Common Causes
Intramuscular hematomas frequently arise from direct trauma, such as a blunt impact, a fall, or a sports-related injury. Severe muscle strains or tears are another common cause. Less frequently, certain medications, such as blood thinners, can increase the risk of hematoma formation. Underlying bleeding disorders can also predispose individuals to developing hematomas.
Recognizing the Signs
Localized pain, which can feel deep and aching, is a common symptom. Swelling in the affected area is noticeable, and a palpable lump or mass may be felt within the muscle. While bruising or discoloration might appear, it can be delayed or less visible if the hematoma is deep. Restricted movement or weakness in the injured muscle can also occur, varying based on the hematoma’s size and location.
Treatment and Recovery
Initial management of an intramuscular hematoma follows the R.I.C.E. protocol:
Rest: Resting the affected muscle prevents further injury and allows healing.
Ice: Applying ice for 15-20 minutes every 2-3 hours during the first 24-48 hours helps reduce bleeding, swelling, and pain by constricting blood vessels.
Compression: Compression with an elastic bandage helps limit swelling and provides support.
Elevation: Elevating the injured limb above heart level promotes fluid drainage and reduces swelling.
Over-the-counter pain relievers like acetaminophen can manage discomfort, but aspirin should be avoided as it can increase bleeding. Recovery timelines vary; minor hematomas often resolve within a few days to a couple of weeks, while larger ones may take several weeks to a few months to fully heal.
When to Seek Medical Care
Seek medical attention if symptoms worsen or new concerns arise. Rapidly increasing pain or swelling, numbness or tingling, or significant weakness or inability to move the affected limb warrant immediate evaluation. Signs of infection, such as increased redness, warmth, fever, or pus, also require professional care. If symptoms do not improve with home care, or if there is concern about an underlying bleeding disorder or medication side effect, medical consultation is recommended. In rare instances, a large intramuscular hematoma can lead to compartment syndrome, a serious condition where increased pressure within a muscle compartment restricts blood flow and can damage nerves and muscles, requiring urgent medical assessment.