A hematoma on the hip is a collection of blood that pools in or around the muscles, bones, or soft tissues of the hip region after blood vessels are damaged. Most commonly the result of a direct blow, a fall, or surgery, these blood collections range from small superficial bruises that resolve on their own to deep, pressurized pockets that compress nerves and require medical intervention. The hip area is particularly vulnerable because of its large muscle groups, proximity to major blood vessels, and the simple fact that it absorbs a lot of impact in everyday falls and contact sports.
What Causes a Hip Hematoma
The most straightforward cause is blunt trauma. A hard fall onto the side of the hip, a collision during a contact sport, or even striking the hip against a piece of furniture can rupture small blood vessels in the muscle or between tissue layers. The hip’s deep muscles, particularly the iliopsoas group that runs along the front of the pelvis, and the gluteal muscles on the back and side, contain a rich blood supply. When those vessels break, blood has nowhere obvious to drain, so it collects in the surrounding tissue.
Falls onto the buttocks and hyperextension of the hip are two mechanisms that have been specifically linked to deep hip hematomas. A subperiosteal hematoma, where blood collects between the bone surface and its outer lining, can develop on the iliac bone (the large wing-shaped bone of the pelvis) after a seemingly unremarkable fall. This type often shows up a few days later with progressive groin or hip pain rather than immediate dramatic swelling, which can make it confusing to diagnose.
Blood Thinners and Spontaneous Hip Hematomas
Not every hip hematoma follows an obvious injury. People taking anticoagulant medications like warfarin can develop spontaneous hematomas in the iliopsoas muscles without any recalled trauma at all. This is a well-recognized complication, and the unsettling part is that it often happens even when the patient’s blood-clotting levels are within the intended therapeutic range.1The Consultant. Spontaneous Iliopsoas Hematoma with Femoral Neuropathy—An Unusual Complication of Anticoagulation In other words, you do not have to be “over-anticoagulated” to develop this problem.
One reported case involved an 85-year-old woman on anticoagulants who developed hematomas in both iliopsoas muscles simultaneously, causing nerve compression in both legs. Her clotting tests were all within the normal treatment range. The larger hematoma on the right side produced more severe nerve symptoms but eventually improved without surgery.2Internal Medicine. Bilateral Iliopsoas Hematomas Complicating Anticoagulant Therapy Warfarin is the most commonly implicated drug, though newer anticoagulants carry similar risks.3PubMed Central. Warfarin-induced spontaneous iliopsoas hematoma – An unusual complication
If you are on blood thinners and develop unexplained groin, hip, or thigh pain, especially with any weakness or numbness in the leg, the possibility of an internal hematoma is worth raising with your doctor promptly. These can grow quickly when the blood’s ability to clot is impaired.
Symptoms That Suggest Something Deeper Than a Bruise
A superficial hip hematoma looks and feels much like a bad bruise: tenderness, swelling, discoloration, and pain with pressure or movement. These usually resolve over a couple of weeks as the body reabsorbs the pooled blood, cycling through the familiar color changes from purple to green to yellow.
Deep hematomas behave differently and can be harder to recognize. Because the blood collects within or between muscles rather than just under the skin, visible bruising may be minimal or absent entirely. Instead, the hallmarks are deep aching pain that gets worse over days, stiffness, and difficulty bearing weight. One particular red flag is nerve involvement. The femoral nerve runs close to the iliopsoas muscle, and a hematoma that grows large enough can compress it, causing weakness when trying to straighten the knee, numbness or tingling along the front of the thigh, and difficulty walking.4PubMed Central. Subperiosteal Hematoma of the Iliac Bone: An Unusual Cause of Acute Hip Pain after a Fall
Sciatic nerve compression is less common but also documented. In one case following hip replacement surgery, a recurring deep hematoma caused sudden foot drop, the inability to lift the front of the foot, weeks after the operation.5PubMed Central. Late sciatic nerve palsy caused by recurrent hematoma after primary total hip arthroplasty: a case report Any new numbness, weakness, or difficulty controlling the leg after a hip injury or surgery warrants prompt evaluation.
How a Hip Hematoma Is Diagnosed
For suspected superficial hematomas, a physical exam alone is often enough. Your doctor presses on the area, checks range of motion, and looks at the skin. When there is concern about a deeper collection, imaging comes into play.
Ultrasound is generally the first-line tool. It is quick, painless, does not involve radiation, and can show the size and location of a blood collection in real time.6PubMed Central. Soft tissue hematomas on ultrasound: a case-based review and practical guide to diagnosis For deeper hematomas or when the full extent of the collection needs to be mapped, CT scans provide a clearer picture, especially for hematomas near bone or within the pelvis. MRI is typically reserved for complex cases where the nature of the collection is uncertain, such as when doctors need to distinguish a hematoma from a tumor or another type of soft-tissue mass.
Treatment for Most Hip Hematomas
The good news is that the majority of hip hematomas, particularly those from sports injuries and minor falls, respond to conservative management. The standard approach involves rest, ice applied to the area, compression, and elevation when practical, along with over-the-counter anti-inflammatory medications for pain.7Clinics in Sports Medicine. Hip and Pelvic Injuries in the Young Athlete The goal in the early phase is to stop the bleeding from expanding. Applying ice in 15- to 20-minute intervals and avoiding heat, massage, or vigorous stretching in the first 48 to 72 hours helps limit the hematoma’s size.
Once the acute pain subsides, gentle range-of-motion exercises and gradual strengthening can begin, ideally guided by a physical therapist. Returning to activity too soon, especially with a deep muscle hematoma, increases the risk of re-bleeding and complications.
For deeper or larger hematomas, particularly those causing nerve compression, the approach depends on severity. A systematic review of iliacus hematoma cases found that roughly half of patients were managed conservatively with pain control, while about 40% required surgical decompression. Complete resolution of symptoms was achieved in just under half of all patients at final follow-up.8Injury. Iliacus hematoma syndrome: A systematic review of recent literature and case report Those numbers reflect the reality that deep hip hematomas with nerve involvement can be slow to fully resolve, and some patients are left with lingering weakness or sensory changes.
When Surgery or Procedures Become Necessary
The decision to intervene typically hinges on whether the hematoma is compressing a nerve and how severe that compression is. The general principle in the literature is that partial nerve deficits can be watched and managed conservatively, but complete paralysis of the affected muscle group is an indication for surgical drainage.9International Journal of Surgery Case Reports. Traumatic iliac muscle hematoma: A rare etiology of quadriceps palsy (case report)
Short of open surgery, ultrasound-guided percutaneous aspiration, where a needle is inserted through the skin to drain the collected blood, is an option for large hematomas. This approach is less invasive but comes with a meaningful recurrence rate. Studies in hemophilia patients with iliopsoas hematomas have reported that about 13% of aspirations either fail or are followed by the hematoma refilling.10PubMed. Iliopsoas hematomas in people with hemophilia: diagnosis and treatment
When a hematoma is being fed by active arterial bleeding, particularly after pelvic or hip surgery, a procedure called transcatheter arterial embolization can be used. A catheter is threaded through a blood vessel to the site of the bleed, and the bleeding artery is sealed off using tiny particles or coils. A study of 22 patients who underwent this procedure for postoperative bleeding after pelvic or hip surgery reported clinical success in over 95% of cases.11PubMed Central. Transcatheter arterial embolization for postoperative arterial complications after pelvic or hip surgery A separate 12-year retrospective study confirmed the safety and effectiveness of this technique for managing bleeding complications after hip surgery specifically.12PubMed. Retrospective 12-year study of the safety and efficacy of transcatheter arterial embolization for managing bleeding complications following hip surgery
Hematomas After Hip Replacement Surgery
Hip replacement is one of the most commonly performed orthopedic surgeries, and postoperative hematomas are a known complication, though the ones serious enough to require a return to the operating room are uncommon. In a large study of nearly 150,000 patients who underwent primary total hip replacement, about 0.12% developed a hematoma that needed reoperation. Several factors increased the risk: a body mass index of 35 or higher roughly doubled the odds, as did operations lasting 100 minutes or more. Patients with a history of bleeding disorders had nearly triple the risk. Concerning downstream effects were also identified: patients who developed a hematoma requiring reoperation faced a dramatically higher risk of deep wound infection (over 20 times the baseline risk), sepsis, and pneumonia.13PubMed Central. Incidence, Risk Factors, and Subsequent Complications of Postoperative Hematomas Requiring Reoperation After Primary Total Hip Arthroplasty
For the vast majority of post-surgical patients, some bruising and minor blood collection around the hip is normal and resolves as healing progresses. The warning signs that something more serious is developing include rapidly increasing swelling, worsening pain that is not responding to prescribed pain medication, new weakness or numbness in the leg, fever, or the skin over the hip becoming taut and shiny. Any of these after hip surgery should prompt a call to your surgeon.
Complications of Untreated or Severe Hematomas
Most hip hematomas heal without lasting problems, but several complications deserve awareness, particularly when a hematoma is large or deep and does not receive appropriate management.
Myositis Ossificans
When a hematoma within a muscle is not properly managed, the body can sometimes respond by depositing calcium and bone-like tissue within the damaged area. This process, called myositis ossificans, transforms what was a soft blood collection into a hard, calcified mass. It is most associated with severe contusions or repeated trauma to the same area and is a well-known risk in contact-sport athletes who take a hard hit to the thigh or hip.14PubMed. Contusions and the Formation of Myositis Ossificans In one case, a woman who fractured her pelvis and was immobilized for an extended period developed ossification in the pectineus muscle near the hip, which was attributed to a combination of the initial injury, prolonged bed rest, and an accompanying traumatic brain injury, all recognized risk factors for this condition.15PubMed Central. Painful and restricted hip due to myositis ossificans circumscripta of the pectineus muscle after pelvic fracture: A case report
The best way to avoid myositis ossificans is proper initial management: rest the injury, apply ice, and avoid aggressive stretching or heat in the early days. Returning to sport too quickly or massaging a deep muscle contusion before it has had time to stabilize increases the risk.
Compartment Syndrome
In rare cases, a large and rapidly expanding hematoma can increase pressure within a closed muscle compartment to the point where blood flow to the tissue is compromised. This is a surgical emergency. In the hip region, the gluteal compartment is the most commonly affected. One case involved a young, otherwise healthy man who developed acute gluteal compartment syndrome after a hip dislocation ruptured the superior gluteal artery. Timely surgical evacuation of the hematoma led to an excellent outcome.16PubMed Central. Gluteal compartment syndrome and superior gluteal artery injury as a result of simple hip dislocation: a case report In another case involving a pelvic fracture, surgeons drained approximately 800 milliliters of hematoma from the deep gluteal compartment during emergency fasciotomy.17Turkish Journal of Emergency Medicine. Gluteal compartment syndrome secondary to superior gluteal artery injury following pelvis fracture: A case report and review of literature
The warning signs are severe, unrelenting pain that seems disproportionate to the injury, extreme pain with passive movement of the hip, visible swelling that feels very tense, and pain that does not improve with strong painkillers. If you or someone near you shows these signs after a hip injury, seek emergency care immediately.
Infection
A hematoma is essentially a pocket of stagnant blood, which can serve as an ideal growth medium for bacteria. In immunocompromised patients, this risk is amplified. One documented case described a patient with uncontrolled diabetes who developed an iliopsoas hematoma that progressed to a full abscess infected with Staphylococcus aureus bacteria, requiring targeted antibiotic treatment.18PubMed Central. Iliopsoas Hematoma Progression to Abscess in the Setting of Diabetic Ketoacidosis Fever, increasing redness, and worsening pain days after an injury or procedure should raise suspicion that a hematoma has become infected.
Morel-Lavallée Lesions
A related but distinct condition worth knowing about is the Morel-Lavallée lesion. This occurs when a shearing force, like sliding along a hard surface during a fall or car accident, separates the skin and its underlying fat layer from the deeper fascia. The resulting space fills with blood, lymph fluid, and fat. The hip and outer thigh are among the most characteristic locations.
These lesions can be tricky because they sometimes develop gradually, presenting as a fluctuant swelling days or even weeks after the initial trauma. In a reported case, a 29-year-old man developed progressive swelling over his right hip and thigh after a fall. Ultrasound showed a fluid collection in the subcutaneous tissue, and aspiration produced serosanguinous fluid (a mixture of blood and serum). MRI confirmed the lesion was acute with no surrounding capsule, and surgical drainage with pressure dressing led to full recovery.19PubMed Central. Morel-Lavallée Lesion of the Hip: A Case Report
If left untreated, Morel-Lavallée lesions can develop a fibrous capsule that encases the fluid, making them chronic and harder to treat. This is why early recognition matters. If you notice a squishy, mobile swelling over the hip that appeared after a sliding or crushing injury, it is worth getting imaged rather than assuming it is a simple bruise.
When a Hip Lump Is Not a Hematoma
A mass or swelling near the hip is not always pooled blood. One condition that can closely mimic a hematoma is hemorrhagic trochanteric bursitis, where the fluid-filled sac over the bony prominence on the side of the hip fills with blood. In rare cases, this can grow large enough to be mistaken for a soft-tissue tumor. A report on two such cases emphasized the importance of carefully ruling out soft-tissue sarcomas, because the imaging appearance of a giant hemorrhagic bursitis can look alarmingly similar to a malignant mass.20PubMed Central. Giant hemorrhagic trochanteric bursitis mimicking a high-grade soft tissue sarcoma: report of two cases
This is not meant to alarm anyone with a bruise on their hip. The overwhelming majority of post-traumatic swellings near the hip are exactly what they seem. But any mass that persists beyond a few weeks, continues to grow rather than shrink, feels unusually firm, or shows up without any recalled injury should be evaluated. Imaging can quickly distinguish a resolving hematoma from something that needs a biopsy, and getting that clarity early is always the safer path.