A black toenail, medically referred to as a subungual hematoma, develops when blood becomes trapped beneath the nail due to repeated trauma. This condition is especially common among runners who engage in frequent or long-distance training. The constant forward motion of the foot inside a shoe causes the toes to repeatedly strike the front, leading to bruising under the nail. Over time, this repetitive impact can damage the nail bed and result in noticeable discoloration.
Early symptoms often include tenderness, pressure, and mild discomfort in the affected toe. As blood accumulates, the nail may turn shades of dark red, purple, or black. Some individuals experience a throbbing sensation, particularly after running or extended physical activity. In more severe cases, the nail may loosen or eventually fall off. This discomfort can interfere with daily activities and make it difficult to maintain a regular training routine without proper care.
The primary cause of a black toenail is repetitive stress linked to running mechanics. Wearing ill-fitting shoes, especially those that are too tight or too short, significantly increases pressure on the toes. Activities such as downhill running or sudden stops can force the toes forward, intensifying the impact. Additionally, poor running form and long training sessions without sufficient rest can further contribute to nail damage and irritation.
Several risk factors increase the likelihood of developing this condition, including long-distance running, wearing improper footwear, and inadequate nail maintenance. Preventive strategies include keeping toenails trimmed, wearing properly fitted running shoes, and choosing moisture-wicking socks to reduce friction. Maintaining proper foot alignment and gradually increasing training intensity can also help minimize stress on the toes. Toe issues can be uncomfortable, and often cause difficulty in running. If toe pain persists, it is suggested that you consult a podiatrist for appropriate treatment and prevention guidance.
Toe pain can disrupt your daily activities. If you have any concerns, contact one of our doctors of Advanced Foot & Ankle Medical Center. Our doctors can provide the care you need to keep you pain-free and on your feet.
What Causes Toe Pain?
Most severe toe pain is caused due to a sports injury, trauma from dropping something heavy on the toe, or bumping into something rigid. Other problems can develop over time for various reasons.
Toe pain can be caused by one or more ailments. The most common include:
- Trauma
- Sports injury
- Wearing shoes that are too tight
- Arthritis
- Gout
- Corns and calluses
- Hammertoe
- Bunions
- Blisters
- Ingrown toenails
- Sprains
- Fractures (broken bones)
- Dislocations
When to See a Podiatrist
- Severe pain
- Persistent pain that lasts more than a week
- Signs of infection
- Continued swelling
- Pain that prevents walking
Diagnosis
In many cases the cause of toe pain is obvious, but in others, a podiatrist may want to use more advanced methods to determine the problem. These can range from simple visual inspections and sensation tests to X-rays and MRI scans. Prior medical history, family medical history, and any recent physical traumatic events will all be taken into consideration for a proper diagnosis.
Treatment
Treatments for toe pain and injuries vary and may include shoe inserts, padding, taping, medicines, injections, and in some cases, surgery. If you believe that you have broken a toe, please see a podiatrist as soon as possible.
If you have any questions please contact our offices located in Agoura Hills, Simi Valley, Thousand Oaks Marin St., and Thousand Oaks Haaland Drive, CA . We offer the newest diagnostic and treatment technologies for all your foot and ankle needs.
