A large hematoma on the buttocks is a deep pocket of trapped blood, usually caused by a hard fall, a direct blow, or sometimes a surgical complication. Most buttock hematomas resolve on their own within one to four weeks, but larger ones can take significantly longer and may need medical drainage. The size, depth, and whether the hematoma is still expanding all determine whether you can manage it at home or need professional intervention.
What Counts as a “Large” Hematoma
A hematoma is different from a regular bruise. While a bruise involves blood that seeps diffusely into tissue, a hematoma is a defined collection of blood that pools in one area and often forms a firm, swollen lump. On the buttocks, the gluteal muscles are thick and well-supplied with blood vessels, so hematomas here can grow surprisingly large before you realize how much blood has accumulated.
In clinical reports, gluteal hematomas measuring 8 centimeters (roughly 3 inches) across are considered large, and some grow big enough to make one side of the buttocks visibly two or three times the size of the other. At that scale, the hematoma isn’t just a cosmetic issue. It can compress nerves, restrict blood flow to surrounding muscle, and take weeks or months to fully reabsorb.
Immediate At-Home Care
If the injury just happened and the hematoma is still forming, your first priority is limiting how much blood continues to pool. Ice is your most effective tool in the first 48 to 72 hours. Apply a cold pack wrapped in a thin towel for 15 to 20 minutes at a time, with at least 20 minutes between sessions. The cold constricts blood vessels and slows bleeding into the tissue.
Compression helps control swelling but is tricky on the buttocks. A wide elastic bandage wrapped around the hips can apply gentle pressure, though it’s hard to keep in place. Don’t wrap so tightly that you feel numbness or tingling. If compression isn’t practical, consistent icing and rest are more important.
Elevation is the standard recommendation for any hematoma, ideally raising the injured area above heart level to slow blood flow and encourage drainage. For the buttocks, this means lying on your stomach or on the opposite side with a pillow under your hips. It’s not as effective as elevating a leg or arm, but it still reduces the pressure driving blood into the injured area.
Avoid anti-inflammatory painkillers like ibuprofen or aspirin in the first few days. These thin the blood and can increase bleeding, which is the opposite of what you want while the hematoma is still fresh. Acetaminophen (Tylenol) is a safer choice for pain during this window.
When You Need Medical Drainage
Small hematomas reabsorb on their own as your body gradually breaks down and recycles the trapped blood. Large hematomas are a different story. When the volume of pooled blood is significant, your body may not be able to clear it efficiently, and the hematoma can become encapsulated, forming a fibrous shell around the blood that prevents natural reabsorption.
A doctor may recommend needle aspiration for a hematoma that remains large and fluctuant (soft and fluid-filled) after the first week or two. This involves inserting a needle or small catheter to draw out the liquefied blood. It’s usually done with ultrasound guidance to ensure the needle reaches the right pocket. You may need more than one aspiration if the hematoma refills.
For very large or organized hematomas that have partially solidified, open surgical drainage may be necessary. This is more common when the hematoma has been present for weeks without shrinking, or when it’s causing symptoms like nerve compression or restricted movement. The surgeon makes an incision, evacuates the clotted blood, and may place a temporary drain to prevent re-accumulation.
Healing Stages and Timeline
A typical hematoma goes through predictable color changes as the blood breaks down: dark purple or blue in the first few days, shifting to green, then yellow-brown as the hemoglobin is processed and cleared. For a large buttock hematoma, expect this process to take considerably longer than a regular bruise. While small hematomas resolve in one to four weeks, large ones can take six to eight weeks or longer, especially deep in the gluteal muscle where the body has limited access to clear the blood.
During the first week, the hematoma is mostly liquid blood and clot. Over the following weeks, enzymes gradually liquefy the clot, and your lymphatic system and small blood vessels carry away the debris. You’ll feel the lump slowly softening and shrinking. Some firmness may linger for weeks after the discoloration fades, which is normal as the last of the fibrous tissue remodels.
Complications to Watch For
Gluteal Compartment Syndrome
This is the most serious potential complication and requires emergency treatment. The gluteal muscles sit within tight fascial compartments, and a large, expanding hematoma can raise the pressure inside those compartments high enough to cut off blood flow to the muscle. When muscle tissue loses its blood supply, it begins to die, a process that also releases toxic proteins into the bloodstream (a condition called rhabdomyolysis, which occurs in roughly 94% of gluteal compartment syndrome cases).
The warning signs are intense, escalating pain that seems out of proportion to the injury, especially pain that gets worse with passive stretching of the hip. Numbness, tingling, or weakness running down the back of your leg suggests the sciatic nerve is being compressed, which happens in about three out of four cases. If you notice these symptoms, get to an emergency room. Compartment syndrome requires surgical decompression, and delays of even a few hours can lead to permanent nerve damage or muscle loss.
Infection
A hematoma is essentially a pocket of stagnant blood, which is an ideal environment for bacteria. If the skin over the hematoma was broken during the injury, or if bacteria enter during aspiration, the hematoma can become an abscess. Signs of infection include increasing redness, warmth, fever, and pain that worsens after the first few days instead of improving. An infected hematoma almost always needs surgical drainage and antibiotics.
Calcification
In rare cases, a deep muscle hematoma can calcify over time, a condition where bone-like tissue forms within the muscle. This happens when severe contusions cause internal bleeding followed by tissue death, and the body’s repair process goes awry, depositing calcium instead of normal muscle tissue. It most commonly affects large muscles of the lower body. If a firm, bony-feeling lump develops at the hematoma site weeks after the injury, imaging can confirm whether calcification has occurred. Treatment depends on whether it causes pain or limits movement.
Morel-Lavallée Lesions
If your hematoma was caused by a shearing force, like sliding across pavement or a heavy lateral impact, the skin and fat layer may have separated from the underlying muscle fascia. This creates a pocket that fills with blood, lymphatic fluid, and dead fat cells. These lesions often take several days to fully develop and can be missed on initial evaluation. They feel like a soft, fluctuant swelling that moves slightly under the skin. Unlike a simple hematoma, Morel-Lavallée lesions frequently need repeated aspiration or surgical treatment because the separated tissue layers don’t reattach on their own.
Returning to Normal Activity
Rushing back to full activity is one of the most common mistakes with a large hematoma. Vigorous movement increases blood flow to the area and can cause re-bleeding, expanding the hematoma right when it was starting to heal. For the first week or two, limit yourself to light walking and avoid sitting directly on the hematoma for prolonged periods. A cushion or donut pillow can take pressure off the area.
Recovery follows a general progression. Once the acute swelling and pain have settled, gentle stretching helps restore range of motion in the hip. When you can stretch without pain, you can begin light strengthening exercises for the glutes, starting with low-resistance movements and gradually increasing load. Contact sports and high-impact activities should wait until you’ve regained full strength, full range of motion, and can use the muscle without pain. For a large hematoma, that timeline is typically four to eight weeks, though it varies based on depth and severity.
If the hematoma was drained surgically, your recovery timeline will be guided by wound healing in addition to the hematoma itself. Expect to avoid strenuous lower-body exercise for at least two to three weeks post-procedure, and follow up with your doctor to confirm the hematoma hasn’t re-accumulated before ramping up activity.