Most hematomas resolve on their own within one to four weeks, though the exact timeline depends heavily on the size of the blood collection, where it is on your body, and your overall health. A small bruise on your arm might fade in 10 days, while a deep muscle hematoma in your thigh could take a month or more. Hematomas in specialized locations, like under a fingernail or inside the skull, follow their own distinct timelines that can stretch to months.
How Your Body Breaks Down a Hematoma
When blood pools outside a damaged vessel, your immune system treats it like debris that needs cleaning up. Specialized white blood cells called macrophages move into the area and begin engulfing trapped red blood cells, a process called erythrophagocytosis. These cells essentially eat the pooled blood, breaking down hemoglobin into a series of pigments that your body can recycle or flush out. Scavenger receptors on the surface of these immune cells play a central role in recognizing and clearing the damaged material while also dialing down inflammation so surrounding tissue isn’t harmed further.
This cleanup process is what drives the familiar color changes you see as a hematoma heals. The initial dark red or purple comes from hemoglobin and its oxygen-carrying variants. After four to five days, the breakdown shifts the pigment toward verdoglobin and then biliverdin, which gives the area a greenish tint. Within another day or two, enzymes convert biliverdin into bilirubin, producing the yellowish color that marks the final stage before the hematoma fades completely.
Timelines by Location
Skin and Soft Tissue
A superficial hematoma, the kind you get from bumping into furniture or taking a hit during sports, typically resolves in one to three weeks. Small bruises at the surface may be gone in under 10 days. Larger collections of blood deeper in the soft tissue take longer because there’s simply more material for your immune cells to process. If the skin above the hematoma stays taut and swollen for more than two weeks without improvement, that’s a sign the blood isn’t reabsorbing normally.
Muscle Hematomas
Deep muscle hematomas, common in the thigh after a direct blow, follow a slower course. A systematic review of athletes recovering from thigh contusions found the average return-to-play time with non-surgical treatment was about 29 days, with a wide range from just a few days for minor injuries to six months for severe ones. The muscle’s blood supply is rich, which helps with healing, but the volume of trapped blood in a deep contusion can be substantial. If recovery stalls past the expected window, imaging to check for a retained or walled-off hematoma is the typical next step.
Under the Nail
A subungual hematoma, the painful dark spot that appears after you slam a finger in a door, doesn’t reabsorb the way a skin bruise does. Instead, the discolored nail has to physically grow out. In a prospective study of patients with nail injuries, the average time for the nail to fully regrow was about four months, though this varied widely, ranging from roughly one and a half to over six months depending on the person. Toenails grow slower than fingernails, so expect a longer wait if the injury is on your foot.
Inside the Skull
Intracranial hematomas, particularly chronic subdural hematomas, operate on a completely different schedule. Even after surgical drainage, resolution takes far longer than most people expect. A study in Frontiers in Neurology found that among patients who had surgery for chronic subdural hematomas, the median time to full resolution was 161 days, roughly five and a half months. Only about 48% of patients had complete resolution at the six-month mark. Some cases took over a year. These hematomas require ongoing monitoring with repeat imaging because they can re-accumulate.
Factors That Slow Healing
Age is one of the biggest variables. Older adults heal more slowly in part because of hormonal changes. Estrogen plays a significant role in regulating inflammation and tissue repair, and declining estrogen levels in both men and women contribute to delayed healing. This is why older adults often notice bruises that seem to linger for weeks.
Blood-thinning medications, including common ones prescribed for heart conditions or blood clots, interfere with your body’s ability to stop bleeding and can allow a hematoma to expand before it stabilizes. If you’re on blood thinners, even minor injuries can produce larger hematomas that take noticeably longer to clear. Chemotherapy drugs can also impair healing, particularly if given within three weeks of an injury, because they suppress the cellular activity needed for tissue repair. Newer cancer drugs that block blood vessel growth are especially problematic, as they directly interfere with the vascular repair that hematoma resolution depends on.
Size matters in a straightforward way: the more blood that’s pooled, the longer the cleanup takes. A pea-sized bruise and a grapefruit-sized hematoma in the thigh involve the same biological process, but the volume of work for your immune cells differs enormously. Location also plays a role because areas with better blood supply tend to heal faster, as more immune cells can access the site.
The Color Stages of Healing
Tracking the color of a hematoma gives you a rough gauge of where you are in the healing process. The key pigments responsible for each stage are well established.
- Days 1 to 2: Dark red, purple, or nearly black. This is fresh hemoglobin and its variants sitting beneath the skin.
- Days 3 to 5: Darker blue or brownish tones as hemoglobin begins to break down.
- Days 4 to 7: Green tints appear as the pigment biliverdin forms.
- Days 7 to 14: Yellow or light brown as biliverdin converts to bilirubin, the final breakdown product.
- Days 14 and beyond: Fading to normal skin color as bilirubin is cleared from the tissue.
These stages often overlap, especially in larger hematomas where the edges may turn green while the center is still purple. If the color progression stalls or reverses, getting darker again after it had started to lighten, that can indicate new bleeding into the area.
When a Hematoma Calcifies Instead of Healing
In some cases, particularly with deep muscle hematomas, the body doesn’t fully reabsorb the blood. Instead, the tissue begins to calcify and form bone-like material within the muscle, a condition called myositis ossificans. This process follows a predictable pattern: within the first four weeks, the area remains soft but swollen. Between weeks four and eight, imaging may show a rim of calcium forming around the edges of the hematoma. Beyond eight weeks, the calcification can mature into a hard, well-defined mass that may persist for months or become permanent.
The risk is highest when a deep muscle hematoma is re-injured before it fully heals, which is one reason athletes are advised not to return to contact activity too quickly after a significant contusion. A hard, painless lump that remains in a muscle weeks after the overlying bruise has faded is the hallmark sign.
Warning Signs of a Dangerous Hematoma
Most hematomas are harmless, but certain situations can become emergencies. The most serious complication from a limb hematoma is compartment syndrome, where the expanding blood collection builds pressure inside a closed space surrounded by dense tissue. The classic warning signs progress in a specific order: pain that seems far worse than the injury should cause, especially pain that intensifies when someone gently stretches the affected muscle. Numbness or tingling follows as nerves get compressed. Weakness in the limb comes next. Loss of a pulse is a late and dangerous sign that means pressure has exceeded what the arteries can push through.
Pain out of proportion to the visible injury is the earliest and most reliable signal. If you have a hematoma on a limb and the pain is escalating rather than gradually improving over the first 24 to 48 hours, that warrants urgent evaluation. Other red flags for any hematoma include increasing size after the first day, skin that feels hot or develops red streaking (suggesting infection), or fever.