Buttock Bruising: Causes, Evaluation, and When to Seek Care

Buttock bruising (contusion/ecchymosis) results from trauma to gluteal tissues. While often minor, it can signal serious underlying issues.

Common Causes

1. Direct trauma: Falls, sports impact, assault.
2. Intramuscular injections: Especially if large volume, wrong site, or patient on anticoagulants.
3. Anticoagulant/antiplatelet therapy: Warfarin, DOACs, aspirin, clopidogrel increase bruising tendency.
4. Bleeding disorders: Hemophilia, von Willebrand disease, thrombocytopenia.
5. Vitamin deficiencies: C (scurvy), K (coagulopathy).
6. Medical procedures: Biopsy, surgery, vascular access.
7. Infections: Cellulitis, necrotizing fasciitis (rare, severe).
8. Malignancy: Leukemia, metastatic deposits, Kaposi sarcoma (rare).
9. Overuse/strain: Weightlifting, intense gluteal exercise.

Red Flags for Urgent Evaluation

• Bruise appears without known injury.
• Large, expanding, or deeply painful.
• Associated with numbness/weakness in leg (sciatic nerve compression).
• Signs of infection: redness, warmth, fever.
• On anticoagulants with elevated INR/bleeding elsewhere.
• History of malignancy or unexplained weight loss.

Diagnostic Approach

• History: Trauma, meds, bleeding history, systemic symptoms.
• Exam: Size, tenderness, neurovascular check, lymph nodes.
• Labs: CBC, PT/INR, PTT, fibrinogen, vitamin levels if indicated.
• Imaging: Ultrasound (hematoma vs. abscess), MRI if deep/suspicious.

Management

• RICE (Rest, Ice, Compression, Elevation) for acute trauma.
• Adjust anticoagulants if INR supratherapeutic.
• Treat underlying disorder.
• Drainage if large tense hematoma compromising nerves/vessels.

Most buttock bruises resolve in 2–4 weeks. Unexplained or recurrent bruising warrants investigation.