A black toenail refers to discoloration of the nail plate, often due to blood pooling underneath it. While frequently benign, this condition can sometimes signal a more serious underlying issue. Knowing the causes and appropriate responses is important for foot health.
Understanding the Causes of Black Toenails
The most frequent reason for a black toenail is trauma or injury, resulting in a subungual hematoma. This occurs when blood vessels beneath the nail burst, causing blood to collect under the nail plate. Trauma can stem from a single acute event, like dropping an object on the toe, or from repetitive impacts, often seen in activities such as running with ill-fitting footwear. The accumulated blood can cause throbbing pain and discoloration, which may appear red, brown, blue, or black.
A fungal infection, known as onychomycosis, is another common cause of toenail discoloration. These infections often start as white or yellow spots and can lead to thickened, brittle, or crumbling nails. The dark appearance can result from debris building up under the nail.
In rare instances, a black toenail can be a symptom of subungual melanoma, a serious form of skin cancer. Unlike a bruise, a dark streak from melanoma typically does not heal or move outward with nail growth and may expand or involve the surrounding skin. Certain medications can also cause nail discoloration, though this is less common.
Safe Self-Care for Minor Cases
For black toenails resulting from minor trauma, self-care measures can help manage symptoms. Immediately following an acute injury, applying the R.I.C.E. protocol (Rest, Ice, Compression, Elevation) can help reduce swelling and pain. This involves resting the foot, applying ice for 10 to 20 minutes at a time, using a light compression wrap, and elevating the foot.
Over-the-counter pain relievers can also provide relief. As the nail heals, the discolored portion will gradually grow out with the new, healthy nail. A toenail can take anywhere from six months to two years to fully regrow, depending on the injury. Maintaining good hygiene by keeping the affected area clean and dry is important during this period.
Avoid attempting to drain blood from under the nail at home. Doing so increases the risk of infection and further injury. Professional medical intervention is necessary for safe drainage if pressure and pain are severe.
When to Seek Professional Medical Care
Seek professional medical care if you experience intense or throbbing pain, especially if it persists. Signs of infection, such as increased redness, swelling, warmth, pus, or fever around the toe, also require prompt medical attention.
Consult a doctor if the nail is significantly lifted or separating from the nail bed, or if the black toenail appears without clear history of trauma. Spreading discoloration that extends into the cuticle or surrounding skin is a concerning sign. If a fungal infection is suspected due to persistent discoloration, thickening, or crumbling of the nail, professional diagnosis is beneficial. Individuals with underlying health conditions like diabetes, peripheral artery disease, or a compromised immune system should consult a doctor for any toenail changes, as these conditions can increase the risk of complications.
Medical Interventions for Black Toenails
Medical intervention for a black toenail depends on the cause and severity. For a painful subungual hematoma, a doctor may perform trephination. This involves creating a small hole in the nail plate using a sterile needle or specialized tool to allow trapped blood to drain, often providing immediate pain relief. This is a quick and relatively painless procedure when performed by a professional.
If a fungal infection is diagnosed, treatment involves antifungal medications. These can be topical solutions or oral medications, which are often more effective for persistent infections. Oral antifungals may require several months of treatment and can necessitate liver function monitoring.
If subungual melanoma is suspected, a biopsy of the nail bed is necessary to confirm the diagnosis. This involves taking a small tissue sample for analysis. For severe trauma or infection, partial or complete removal of the nail (nail avulsion) might be required to treat the nail bed or allow for healing. A doctor might also refer patients to specialists like a dermatologist or a podiatrist.
Preventing Future Black Toenails
Preventing black toenails involves proper foot care and footwear. Ensuring shoes fit correctly is important, especially for activities like running. Shoes should have ample space in the toe box to prevent repeated toe impact.
Regular nail care also plays a role. Toenails should be trimmed short and straight across to avoid injury and reduce pressure against shoes. Wearing moisture-wicking socks can help keep feet dry and prevent them from sliding forward, minimizing friction and impact.
For those involved in sports or activities where toe injuries are common, wearing protective footwear can offer additional safety. Promptly addressing fungal infections is also important, as these can weaken the nail and make it more susceptible to damage.