The natural color of toenails is a soft transparent white. However, you can see changes in color from white or yellow to black due to a variety of causes, including trauma, hematoma and fungal infections among many others. Black toenails are characterized by bruising or bleeding under the nail.
Black toenails are especially common among athletes and runners, especially those that undergo rigorous training.
Causes for Black Toenails
Black toenails can be caused by trauma as a result of running or wearing shoes that do not fit well. If you notice the color of your toenails changing from normal to black after a workout or as a result of wearing tight shoes, it’s likely a result of trauma.
Trauma can be in two forms, mild or severe. Mild trauma is when you notice a black and/or blue discoloration under the nail. If you have a mild toenail trauma, you may not require medical treatment, because the black nail will naturally grow out.
However, if it is severe, the blisters under the nail can remove the nail partially or totally from the nail bed. It can be very painful if the nail does not detach completely from the bed. Once the nail detaches completely, it is dead and the pain will subside and vanish quickly.
A new nail can grow in the nail bed. This will usually take between 3 to 6 months for smaller toenails and up to a year for big toenails.
Another way you can get a black toenail is if you accidentally drop a heavy object on your foot or you stub your toe against a hard object. These actions can puncture the blood vessels under your nail bed and cause blood to gather underneath.
The blood will appear dark underneath the nail after the incident. The collected blood under the nail bed causes a painful sensation, swelling and throbbing. You can reduce this pain by using a needle to prick the nail so that the blood can come out. This process is best carried out by your Houston podiatrist.
- Fungal Infections
The third causative factor of a black toenail is fungal infections (Onchomycosis). Nail fungal infections affect 5% of the general population. Your toenails can easily get infected because fungi thrive in the moist and warm environments provided by daily footwear. You can also easily pick up a toenail fungal infection as you walk around a swimming pool or locker rooms.
These infections can spread to your toenails, changing their color from normal to shades of blue, green, yellow, purple or black. When you notice one of these unexpected colors spreading on your toenail, it is probably due to the presence of a fungal infection.
The range in color is due to the presence of subungal debris – a chalk-like substance that is found inside the nail bed.
Once you notice that you have a fungal infection, see your podiatrist. In addition to confirming the presence of a fungal infection, your foot specialist can offer various treatments, including laser nail fungus treatment.
These aren’t the only potential causes of black toenails. Some people also develop black toenails as a result of skin cancer or changes in skin tone, both of which will differ in appearance from the causes described above.
Houston podiatrist Gabriel Maislos, DPM, FACFAS, specializes in treatment of the foot and ankle, including disorders affecting the toenail, such as ingrown toenails, nail fungus and crush injuries. Please call (713) 541-3199 to schedule an appointment with Dr. Maislos.We accept most forms of major medical insurance.
Call (713) 541-3199 if you experience:
- blackening or discoloration of the toenail
- toenail pain or discomfort
- thick, detached nail or blistering around the nail bed