Under normal circumstances, our toenails are a glassy, somewhat opaque colour. The protective proteins of our toenails, called alpha-keratin, create this consistency. Together with the skin below it, healthy toenails should be pink. Sometimes, however, our toenails change colour. But why?
You may experience toenail discolouration from damage to the toenail itself or from damage to the skin below the nail bed. In both instances, a black spot may appear. It can be a black spot below the toenail, or your toenail itself may change colour.
This article teaches more about black spots under toenails, different kinds of toenail discolouration, and treatments. First, let’s explore the nail condition of a black toenail.
What’s a black toenail?
Black toenails are a type of nail condition characterized by damage to the skin below the nail. In most cases, a black toenail is a subungual hematoma, especially if you see a black spot. The black area you see is a bruise (a blood vessel breakage causing bleeding near the skin surface.)
However, your toenail may turn black for other reasons. We break down the causes below.
Should I be worried about a black toenail?
Black toenails have several causes, some more common than others.
- A subungual hematoma is the most common cause of a black spot under your toenail. Trauma, whether acute or chronic, causes a black spot under your toenail. Instances like running with ill-fitting footwear, stubbing a toe, or dropping an item on your toe are common culprits. Due to its length and weight-bearing role, your big toe is the most common toenail for a subungual hematoma. Your toenail may fall off entirely, or you may experience a small black spot. If the latter, you can trim off the black area as your nail grows out.
- You may associate a fungal infection with discolouration of the toenail. Although usually a yellow-green, your toenail may also turn black.
- In rare cases, ingrown toenails can be the culprit for a black toenail. An ingrown toenail causing a black toenail is usually related to a complication of a previous toenail treatment.
Rare and more severe causes
- Malignant melanoma can cause a black toenail: Cancer forms in the cells of our skin that give our skin colour, which causes a black spot.
- A B12 deficiency: B12 keeps your nails strong and healthy. A lack of B12 may result in a blackish tint.
- Kidney problems
- Liver disease
- Linear melanonychia can cause black and brown lines that run either with your toenail or horizontally across your toenail.
If you have doubts about the black spot under your toenail, book an appointment with a chiropodist for the next steps and a diagnosis.
What kind of discolourations of a toenail are there?
In addition to black toenails, you may experience other discolouration. Click here to learn about the various shades and causes of discoloured toenails.
How can I treat a discoloured (including a black) toenail?
If you can connect the cause of a black toenail to a common cause—for instance, a stubbed toe—then at-home treatments are sufficient. However, if you haven’t had any trauma or damage to your nail, consult a medical professional for treatment options. Here are some ways you can treat a discoloured toenail:
Let it grow out
If your toenail isn’t damaged or at risk of falling off, the most effective action is to let the toenail grow out. Expect to wait between 6-9 months to allow your toenail to grow out thoroughly and to be able to trim the black area away.
Cover the toenail
If your toenail dies and falls off, you should cover any exposed parts of the nail bed for 7-10 days. Coat the area with a non-stick bandage and wait for the skin underneath to harden. Once the skin hardens, you can leave the nail and allow it to grow back or use an artificial nail to improve aesthetics.
Visit a chiropodist or foot doctor
If you have damage to your toenail from trauma and need guidance and treatment, visit a chiropodist. Our team of dedicated licensed chiropodists is committed to providing quality care and services for all your foot and ankle needs. They can diagnose, treat and help manage various foot conditions, from callus removal to ingrown toenails to bunions.
Over-the-counter creams and ointments
Ointments and creams are usually effective and can help treat fungal infections. You can also use a prescription antifungal treatment for severe cases of toenail infections.
Buy a new pair of shoes
If you have poorly-fitting shoes causing stress to your toenail, invest in proper footwear for your feet.