You can bruise your toenail, a common occurrence often resulting from trauma. This condition, medically known as a subungual hematoma, describes bleeding that occurs underneath the nail plate. While often painful, it is typically not a serious medical condition.
The Nature of a Bruised Toenail
A bruised toenail develops when blood vessels underneath the nail bed rupture, causing blood to collect and become trapped between the nail plate and the underlying tissue. This pooling of blood leads to discoloration of the nail. The appearance of a subungual hematoma changes over time; initially reddish or purple, it progresses to dark brown or black as blood clots and dries. This accumulation of blood creates pressure, which is the primary cause of throbbing pain and tenderness. In some instances, significant pressure can cause the nail plate to separate from the nail bed.
Common Causes and Prevention
Bruised toenails commonly result from direct impact or repetitive stress. Dropping a heavy object on the foot or stubbing a toe are frequent causes of acute trauma. Repetitive micro-trauma, such as that experienced during running or hiking, can also lead to a bruised toenail, often called “runner’s toe” or “black toenail.” This injury often occurs when toes repeatedly press against the front or top of a shoe.
Prevention involves proper footwear and awareness. Ensuring shoes fit well is important, with adequate space in the toe box to prevent toes from pressing against the shoe, especially during physical activity. Regularly trimming toenails short also helps, as long nails are more prone to impact within shoes. Wearing appropriate protective footwear where foot trauma is possible, and maintaining awareness of your surroundings, can reduce the risk of injury.
At-Home Care and When to See a Doctor
For a bruised toenail, at-home care can help manage discomfort. Apply ice wrapped in a cloth to the affected toe for 20-minute intervals to reduce swelling and pain. Elevating the foot also helps minimize swelling, and over-the-counter pain relievers can alleviate discomfort. Rest the foot and avoid activities that put pressure on the injured toe.
While many bruised toenails resolve with home care, seeking medical attention is important in certain situations. See a doctor if the pain is severe or worsens, if the bruise covers a large portion of the nail (more than 25-50%), or if there are signs of infection such as increased redness, swelling, warmth, pus draining from under the nail, or fever. A medical professional should also be consulted if you suspect a bone may be broken, if the nail appears to be significantly lifting or tearing, or if the injury causes cuts to the surrounding skin. In cases of severe pressure and pain, a doctor may perform a procedure called trephination to drain the pooled blood by creating a small hole in the nail, providing immediate relief. This procedure should never be attempted at home due to the risk of infection and further damage.