The most common cause of black toenails among runners is bruising (bleeding) under the nail. Repetitive trauma of the shoe bumping the toenail can also cause the nail to thicken.
If the nail became suddenly painful, a podiatrist may need to puncture the nail to release the blood and ease the pressure. This is often the result of trauma, such as being stepped on or dropping a heavy object on the toe.
A fungal infection can discolor and thicken toenails. Treatment options include oral and topical medication. The two newest topical prescription medications are Jublia and Kerydin. Testing the nail can often identify the causative organism.
Most concerning, a black spot under or in a nail that does not go away can be a melanoma (skin cancer). Please have a podiatrist check it. A biopsy may be needed. The famous reggae singer and musician Bob Marley died from melanoma that started in a toenail.
At Skokie Foot and Ankle Specialists we provide attentive care and are trained to perform these tests, usually in our office. If you have any concerns regarding the appearance of your nails, we urge you to call us at (847) 675-3400 or click here for an appointment.