Runner’s toe, formally known as a subungual hematoma, is a common foot ailment resulting from trauma to the toenail during physical activity, especially running. This condition occurs when blood vessels beneath the nail bed rupture, causing blood to pool under the toenail plate. It is a frequent occurrence for distance runners who subject their feet to repetitive, high-impact stress. Understanding the appearance, causes, and management of runner’s toe is important for anyone engaging in high-impact exercise.
Visual Indicators of Runner’s Toe
The most recognizable sign of runner’s toe is the change in toenail color due to the accumulation of blood underneath the nail plate. Initially, the area may appear dark red, blue, or purplish, indicating fresh bleeding in the nail bed. As the pooled blood ages and oxidizes, the discoloration progresses to a darker brown or black hue.
The size of the discolored area can vary from a small spot to covering the entire nail, often affecting the big toe because it protrudes the furthest. The pressure created by the blood collection can eventually cause the nail plate to separate from the nail bed, making the nail feel loose or resulting in the loss of the toenail. This separation is a physical response to the hematoma pushing the nail upward.
Physical Sensations and Symptoms
Runner’s toe is characterized by physical feelings that range from mild discomfort to acute pain. The most prominent sensation is a throbbing or intense pressure directly beneath the toenail, resulting from fresh blood accumulating in the small space between the nail plate and the nail bed.
The affected toe is often tender to the touch, and even light pressure, such as wearing a shoe or walking, can cause significant discomfort. If the pressure is not relieved, the pain can become severe enough to interfere with normal walking or running activities. Swelling around the affected toe may also occur due to the underlying trauma.
Primary Causes and Risk Factors
Runner’s toe is caused by repetitive microtrauma, where the toenail repeatedly strikes or rubs against the inside of the shoe. This continuous impact damages the small blood vessels in the nail bed, leading to the bleeding that forms the subungual hematoma. Long-distance running increases this risk because the foot naturally swells, reducing the available space within the shoe.
Ill-fitting footwear is a major contributor, particularly shoes with a toe box that is too short, too tight, or too loose. If the shoe is too short or too loose, the foot slides forward, causing impact. Running downhill exacerbates the problem by forcing the foot toward the front of the shoe with greater momentum. Untrimmed or long toenails also increase the contact and friction with the shoe’s interior, making trauma more likely.
Treatment and Prevention Strategies
For an existing runner’s toe that is not severely painful, treatment involves allowing the body time to reabsorb the blood, which can take several months as the nail grows out. If the pressure causes intense or persistent pain, a podiatrist may perform nail trephination, which involves safely draining the blood through a small hole drilled in the nail plate to relieve the pressure. Attempting to drain the blood at home should be avoided, as it carries a high risk of infection.
Prevention focuses on mitigating the repetitive trauma that causes the condition.
- Ensure proper shoe fit, leaving a thumb’s width of space between the longest toe and the end of the shoe to accommodate for foot splay and swelling during a run.
- Employ lacing techniques, such as a heel lock, to secure the foot and prevent it from sliding forward inside the shoe, especially on downhill sections.
- Regularly trim toenails straight across.
- Wear moisture-wicking socks to reduce friction and slippage.