Medically reviewed by Dr. Tom Biernacki, DPM — Board-Certified Podiatric Surgeon — Balance Foot & Ankle, Howell & Bloomfield Hills, MI. Last updated April 2026.

A subungual hematoma — bleeding beneath the nail plate from direct trauma, repetitive microtrauma from running, or crushing injury — is one of the most painful acute nail conditions encountered in podiatric practice. Appropriate management depends on hematoma size, time elapsed since injury, and whether nail plate disruption warrants exploration for underlying nail bed laceration.

Mechanisms of Injury

Acute subungual hematoma results from direct impact (dropping a heavy object, kicking a fixed object) that ruptures the subungual blood vessels between the distal phalanx and the nail plate. Repetitive microtrauma hematoma — “runner’s toe” or “black toenail” — accumulates gradually from the nail plate impacting the toe box with each footstrike, particularly in shoes with inadequate toe box depth or during prolonged downhill running that drives the toes forward. The great toenail and second toenail are most commonly affected.

When to Trephinate

Trephination (decompression of the hematoma by creating a small hole through the nail plate) is indicated when: hematoma covers more than 25–50% of the nail plate area, pain is severe, and presentation is within 48 hours of acute injury before clot organization. The procedure uses a heated wire (electrocautery), rotary drill, or 18-gauge needle to create a small opening through the nail plate over the hematoma — releasing the accumulated blood and immediately relieving pressure and pain. Post-trephination care includes cleansing, protective dressing, and daily wound inspection for infection signs. Trephination is unnecessary for small hematomas (<25%) or those older than 48–72 hours, where observation and nail protection are appropriate.

Nail Plate Disruption and Nail Bed Laceration

Complete nail avulsion at the time of injury requires exploration of the nail bed for laceration — particularly for injuries with hematoma involving more than 50% of the nail area, which has a high correlation with underlying nail bed laceration. Nail bed lacerations are repaired with 6-0 absorbable suture to restore the smooth nail bed surface that guides normal nail regrowth. The original nail plate is replaced as a biological splint over the repair or a non-adherent nonadherent dressing is used if the original plate is damaged beyond reuse.

Nail Regrowth and Prognosis

Toenail regrowth following complete nail loss proceeds at approximately 1–1.5mm per month from the nail matrix — requiring 12–18 months for complete great toenail regrowth. Patients should expect nail plate dystrophy (ridging, thickening, color change) in the new nail during the regrowth period. Permanent nail dystrophy results from nail matrix damage — a risk with severe crush injuries, deep lacerations involving the matrix, or repeated trauma to the same nail. Protective nail splints and wider toe box footwear during regrowth prevent repeated microtrauma during the vulnerable period.

Nail Injury Care at Balance Foot & Ankle

Dr. Biernacki at Balance Foot & Ankle provides trephination, nail bed laceration repair, and nail avulsion procedures with same-day appointments for acute nail injuries. Evaluation and management of runner’s toe and chronic nail microtrauma from footwear fit issues are also available. Call (810) 206-1402 for a same-week or urgent nail injury evaluation.

Toenail Injury Treatment in Michigan

Subungual hematomas (blood under the toenail) from trauma need proper treatment to relieve pressure and prevent nail loss. Our podiatrists perform painless trephination and manage the full range of traumatic nail injuries.

Get Quick Toenail Injury Treatment → | Book Your Appointment | Call (810) 206-1402

Clinical References

1. Roser SE, Gellman H. “Comparison of Nail Bed Repair Versus Nail Trephination for Subungual Hematomas in Children.” Journal of Hand Surgery. 1999;24(6):1166-1170.
2. Simon RR, Wolgin M. “Subungual Hematoma: Association with Occult Laceration Requiring Repair.” American Journal of Emergency Medicine. 1987;5(4):302-304.
3. Seaberg DC, et al. “Outcome of Patients with Simple Subungual Hematomas.” Annals of Emergency Medicine. 1991;20(10):1142.

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Dr. Tom Biernacki, DPM

Dr. Tom Biernacki, DPM is a double board-certified podiatrist and foot & ankle surgeon at Balance Foot & Ankle Specialists in Southeast Michigan. With over a decade of clinical experience, he specializes in heel pain, bunions, diabetic foot care, sports injuries, and minimally invasive surgery. Dr. Biernacki is a member of the APMA and ACFAS, and his patient education content on MichiganFootDoctors.com and YouTube has reached over one million views.