Most hematomas heal on their own with basic home care. A mild hematoma typically resolves in about five days, while a larger one can take weeks to months, gradually changing color and shrinking as your body reabsorbs the pooled blood. The key is managing swelling early, switching strategies as healing progresses, and knowing which signs mean you need professional help.
A hematoma is different from an ordinary bruise. Where a bruise involves blood seeping into surrounding tissue, a hematoma is a distinct pocket of blood that collects outside a blood vessel, usually after a blow or injury. That pooled blood creates a firm, swollen lump that your body has to actively break down from the inside out.
What Happens Inside a Healing Hematoma
Within hours of the injury, your immune system sends specialized white blood cells called macrophages to the site. These cells physically engulf and digest the trapped red blood cells and clotted material, breaking them down into components your body can recycle or flush away. This cleanup process is what drives the familiar color changes: red or dark purple in the first few days, shifting to blue, then green and yellow as the blood pigments are chemically broken down.
Understanding this process matters because many of the home treatments below work by supporting it. Cold therapy limits the initial pooling. Heat therapy later on brings more blood flow to the area, delivering more of those cleanup cells. Anything that disrupts blood flow or re-injures the area slows the whole cycle down.
First 48 Hours: Cold, Compression, Elevation
The first two days are about limiting the hematoma’s size. Apply an ice pack wrapped in a thin towel for 15 to 20 minutes every two to three hours. Some experts recommend a more conservative approach: 10 minutes on, 20 minutes off, repeating that cycle two or three times, and stopping ice application entirely within six hours of the injury. Either way, never place ice directly on skin.
If the hematoma is on a limb, wrap it with a compression bandage snugly enough to provide support but not so tight that you lose feeling or see skin color changes below the wrap. Elevate the injured area above the level of your heart whenever you can. This reduces the pressure pushing blood into the damaged area and helps limit throbbing and swelling. Even propping a leg on a couple of pillows while you sleep makes a difference.
After 48 Hours: Switch to Heat
Once the initial swelling has stabilized, usually after 48 to 72 hours, transition to warm compresses. A warm (not hot) towel or heating pad applied for 15 to 20 minutes several times a day increases blood flow to the area. That fresh circulation delivers more macrophages to break down the pooled blood and carries away waste products. Prolonged icing beyond the first two days can actually slow healing by restricting the blood flow your body needs for cleanup.
This is also when gentle movement becomes important. If the hematoma is over a muscle or joint, start with pain-free range-of-motion activities like normal daily tasks. Avoid aggressive stretching or massage directly over the lump during this phase. Pushing too hard too early on a deep muscle hematoma can trigger a complication called myositis ossificans, where bone-like tissue forms inside the muscle. Wait until you can move the area through its full range without pain before progressing to stretching or strengthening exercises.
Topical Treatments That Help
Arnica gel or ointment is the most studied topical option. In a controlled trial comparing several treatments, a 20% arnica preparation reduced bruising significantly more than placebo and more than a low-concentration vitamin K formula (1% vitamin K with retinol). A 5% vitamin K cream performed similarly to the arnica. If you want to try a topical, look for arnica ointment with a higher concentration and apply it twice a day. These products work best on superficial hematomas close to the skin surface and won’t do much for deep tissue collections.
Pain Relief Without Making It Worse
Acetaminophen (Tylenol) is the safest choice for pain from a hematoma. Aspirin should be avoided entirely because it thins the blood and can cause the hematoma to expand. The picture with other anti-inflammatory painkillers like ibuprofen and naproxen is more nuanced. These drugs do have mild blood-thinning effects, and some surgical studies have shown trends toward increased bleeding with their use. For a fresh hematoma in the first 24 to 48 hours, sticking with acetaminophen is the more cautious approach. If you’re already taking a blood thinner for another condition, that’s worth mentioning to your doctor, as these medications can cause hematomas to grow significantly larger than they otherwise would.
When a Hematoma Needs Medical Drainage
Most hematomas under the skin don’t need any procedure. But some situations call for professional intervention. A hematoma that keeps growing, feels increasingly tense, or causes severe pain may need to be drained with a needle or a small incision. Hematomas that sit in tight spaces, like under a fingernail or toenail, are a common example. Doctors typically recommend draining a subungual (under-the-nail) hematoma when it covers 50% or more of the nail, or 25% or more if there’s also a fracture underneath. Smaller ones can be left alone.
Hematomas inside the skull are a different category entirely. An epidural hematoma, the type that forms between the skull and the brain’s outer covering after head trauma, can be life-threatening and requires emergency surgery when it’s large enough to compress brain tissue. These are not the kind of hematoma you manage at home.
Warning Signs That Need Immediate Attention
A hematoma in an arm or leg can, in rare cases, create enough pressure inside a muscle compartment to cut off circulation. This is called compartment syndrome, and it’s a surgical emergency. The earliest reliable sign is pain that seems out of proportion to the injury, especially a burning or deep aching sensation that gets worse when the muscle is gently stretched. You may also notice tingling, numbness, or a “pins and needles” feeling in the area.
The classic textbook signs of compartment syndrome (no pulse, paralysis, pale skin) are actually late findings that mean tissue damage is already advanced. Don’t wait for those. If a hematoma in a limb is producing worsening pain, tightness that feels like the skin can’t stretch any further, or new numbness, get to an emergency room.
Other reasons to seek medical evaluation: a hematoma that appears without any clear injury, hematomas that keep recurring, one that shows signs of infection (increasing redness, warmth, fever, or pus), or a hematoma on the head after a significant impact.
Realistic Healing Timeline
A small, superficial hematoma from a minor bump will typically look and feel normal again within five days. A moderate hematoma, the kind that leaves a firm, golf-ball-sized lump, often takes two to three weeks to fully flatten and lose its discoloration. Large or deep hematomas can persist for a month or longer, slowly softening and changing color as they’re reabsorbed. The yellow-green stage near the end of healing can look alarming, but it’s actually a sign that the breakdown process is nearly complete.
If a hematoma hasn’t noticeably started shrinking after two weeks, or if it hardens rather than softening over time, that’s worth having a doctor evaluate. A hardening hematoma may be calcifying, and early intervention can prevent it from becoming a permanent lump.