The medical term for black toenails is subungual hematoma and is defined as having a collection of blood between the toenail and the nail bed, which is a result of direct or repetitive trauma to the area. A build up a fluid can lead to emery pressure which leads to pain. In running, typically the tight toe-boxes (poor fitting shoes), downhill running, pronation, toe deformities or incorrect lacing techniques result in black nails.
Any redness around the cuticle, loss of sensation or pain should be checked out by a medical professional or a podiatrist. Typically, these nails dry out within a week or two and fall off if enough damage is done to the nail. The new nail forms within a few months and typically grow out normally. Soaking the affected toes for the first few days in salty water can help and applying an antiseptic cream with a plaster can give pain relief if its tender.
A lot of runners may attempt to lance the nail/pop the blister using a sterile needle. This is not recommended unless in extreme circumstances. The problem with the needle method is that most of the time the needle become a portal of entry for bacteria into a sterile area under the nail and if the needle has been heated using an open flame, the carbon molecules that form on the needle can be also introduced into the area, which isn’t best.
Tips to prevent black nails
- Alternate training routes (alternating the routes reduces or changes the repetitive trauma to the toes during the run compared to running the same route each time.)
- Check the fitting of your running shoes to ensure adequate space in front of your toes.
- Replace old running shoes regularly, as a new shoe will give you better cushioning and support to your foot, which could help reduce the pressure on your toes
- Check with your local running shoe shop or local podiatrist about possible different lacing techniques to assist your space of foot.
Calvin Sinnett is a qualified podiatrist whose focus is to manage and correct lower limbs and foot problems & disease complications. He also has a special interest in sports podiatry and runs a private practice in Edenvale and Constantia, Johannesburg. Read more about Calvin Sinnett
Please note that information found in these articles does not constitute medical advice. If you are experiencing an injury or condition of any kind, it is always advisable to contact a medical professional for advice on your specific symptoms.