Short answer: Your toenails can turn black and fall off from the repeated impact of your toes hitting the front of your running shoes. This impact can cause bleeding under the nail, making it look black. Over time, the damaged nail may fall off, allowing a new nail to grow in its place.
Why Toenails Turn Black From Running
Running, especially over long distances, often causes your toes to repeatedly collide with the front of your shoes. This constant impact can result in a condition called subungual hematoma, where blood pools under the nail. The pooling blood gives the nail a black or dark blue appearance, resembling a bruise. You’ll usually notice this discoloration after longer runs when the repeated trauma has accumulated.
In addition to discoloration, the toenail may feel tender or throb, especially if the pressure builds up beneath it. This can affect one or several toenails, often the big toe, due to its size and position in the shoe. The repeated trauma can weaken the nail’s attachment to the nail bed, eventually causing it to loosen and fall off.
Managing Black Toenails at Home
At home, the first step is to ensure your foot hygiene is optimal. Keep your feet clean and dry, which helps prevent infections from developing around the nail. Trim your nails straight across to prevent them from snagging or catching on shoes or socks. If there’s discomfort, apply an ice pack wrapped in a cloth to reduce swelling and pain. Over-the-counter pain relief, such as acetaminophen or ibuprofen, can help alleviate tenderness.
To prevent further issues, consider adjusting your running technique or footwear. Make sure shoes fit properly, with enough room in the toe box to prevent repeated impact on the toenails. Consider running socks with more cushioning to reduce friction. Silicone toe protectors can also be useful for shielding nails from trauma during runs.
How a Podiatrist Can Help
If your blackened toenail causes persistent discomfort or shows signs of infection, a visit to a podiatrist is recommended. A podiatrist can perform a procedure known as nail trephination to carefully drain the blood beneath the nail, relieving pressure and pain. This procedure is typically quick and causes minimal discomfort.
A podiatrist can also assess if there’s any underlying issues contributing to toenail problems, such as structural foot abnormalities or improper footwear. We can help you find shoes that fit properly, reducing further risk of injury, and provide guidance on injury prevention techniques.
If the toenail falls off and the nail bed is exposed, a podiatrist can offer treatments to protect and help heal the area. They may also provide advice on supplements or dietary changes that can promote better nail health and growth.
When to See a Podiatrist
Persistent pain or pressure under the nail that doesn’t improve with home care
Signs of infection, such as redness, swelling, warmth, or pus around the nail
The nailbed seems damaged, or the toenails fall off repeatedly without clear cause
You have diabetes or circulation issues, increasing the risk of complications
A new nail does not seem to grow back correctly, or there are changes to the structure or color of a regrowing nail
If you experience any of these symptoms or your toenail issues persist, don’t hesitate to seek professional care. Visit us at Black Toenail Causes. At DeNiel Foot & Ankle Center in Houston, we’re here to help you find relief from toenail issues and get back to enjoying your activities comfortably and safely.
