A hematoma looks like a bruise, but it’s typically darker, more swollen, and firmer to the touch. While a regular bruise is a flat discoloration under the skin, a hematoma involves a larger pool of blood collecting outside a blood vessel, often creating a raised, tender lump. The exact appearance depends on where in the body it forms and how deep the blood sits beneath the surface.
Hematoma vs. Bruise: The Visual Difference
A standard bruise happens when small veins and capillaries under the skin break, allowing a thin layer of blood to spread through surrounding tissue. The result is a flat, discolored patch that’s tender but not raised. A hematoma is a more concentrated pooling of blood. Instead of dispersing thinly, the blood collects into a defined pocket, which is why hematomas often look like a swollen, dark lump rather than a flat mark.
Shallower hematomas cause visible color changes on the skin’s surface. They range from tiny pinpoint dots (called petechiae) to larger purple patches to the size of a fist or bigger. A deep hematoma, buried in muscle tissue, may not show any surface discoloration at all. Instead, you’ll notice swelling and feel a firm, spongy mass underneath the skin that feels distinctly different from normal tissue. Pressing on the area with your fingers is often the clearest way to tell a hematoma apart from a simple bruise, because the pooled blood creates a noticeable lump with defined edges.
Color Changes as a Hematoma Heals
A hematoma follows a predictable color progression as your body breaks down the trapped blood. It starts as a pinkish-red or bright red mark shortly after the injury. Within hours to a day or two, it shifts to a deep blue or dark purple. Over the following days, the color fades through violet and green, then to a dark yellow, and finally a pale yellow before disappearing entirely.
A typical surface bruise completes this entire cycle in about two weeks. Larger hematomas take longer because there’s simply more blood for your body to reabsorb. A significant hematoma on your thigh or calf, for example, can take three to four weeks or more to fully resolve. During healing, you may notice the edges of the discoloration changing color faster than the center, giving the hematoma a ring-like appearance with multiple colors visible at once.
What a Hematoma Looks Like Under a Nail
A subungual hematoma, the kind you get from slamming a finger in a door or dropping something heavy on your toe, has a distinctive look. The nail turns black-and-blue or black-and-purple as blood pools in the tight space between the nail and the nail bed. The color may start red or purple and gradually darken to brown or black over the following days.
The pressure from the trapped blood can cause the hard part of the nail to lift away from the tissue underneath. Even gentle pressure on the nail can be extremely painful, and throbbing pain is common. If the nail lifts significantly or the pain is severe, it’s worth getting an X-ray. The same force that caused visible bleeding under the nail can also fracture the bone underneath, and that injury isn’t visible from the surface.
Hematomas You Can’t See
Not all hematomas show up on the skin. Internal hematomas, particularly those inside the skull, produce no visible bruising at all. After a head injury, an epidural hematoma (bleeding between the skull and the brain’s outer covering) announces itself through symptoms rather than appearance. The most telling sign is one pupil becoming noticeably larger than the other. Weakness on one side of the body, confusion, severe headache, and loss of consciousness are other warning signs. Unequal pupil size after any head trauma is a medical emergency.
Deep muscle hematomas also stay hidden from view. A hematoma buried in the quadriceps or gluteal muscles may only show up as a firm, swollen area that’s warm and painful to touch. You might notice the limb looks slightly larger on the affected side compared to the other, but no bruise-like discoloration appears on the skin because the blood is too deep for the color to show through.
Signs a Hematoma Needs Medical Attention
Most surface hematomas heal on their own with rest, ice, and time. But certain features suggest something more serious. A hematoma that keeps growing over hours rather than stabilizing could mean active bleeding that isn’t stopping on its own. Increasing tightness or a sensation of pressure in the area, especially in the forearm or lower leg, can signal that the pooling blood is compressing nearby structures.
A hematoma that stays firm and doesn’t begin shrinking after a week or two may need to be drained. Skin that becomes hot, increasingly red, or develops streaking around the hematoma could indicate infection in the collected blood. And any hematoma that appeared without a clear injury, or that seems out of proportion to a minor bump, is worth investigating since it can occasionally point to a bleeding disorder or medication side effect.