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5 Causes of Black Toenails

It can be quite startling to pull your sock off and spot a black toenail. For some people, it may be only a black dot under the nail, while for others, the entire nail may be dark. But rest assured, as disturbing as it may appear, a black spot on your nail is usually not serious. Read on to discover five reasons why you may have black toenails, and what you can do to treat and prevent them.

1. Singular Injury

Ouch! A trauma, such as stubbing your toe or dropping a heavy object on it, can cause a black nail. This happens because the force of the object breaks blood vessels under the nail, causing a pooling of blood that appears dark. The toe may also be sore and sensitive to touch. While this type of black toenail can resolve on its own, you may need to see a chiropodist to have the blood drained.

2. Repeated Injury

Have you increased your running distance as part of your New Year’s resolution? What feels great for your body may not always be so great for your toes. When you run longer distances, your toes can get squished up against or repeatedly hit the inside of your shoes, especially if you are not wearing the right running shoes. Over time, this causes bruises and blood blisters to form under the nail, giving your toenails a black colouring. Your dark nail should grow out in six to nine months, but make sure you are wearing properly fitting shoes for each run. If your nail begins to lift off or falls off all together, see your chiropodist.

3. Fungal Infection

While most fungal infections under the toenail are a white or yellowish colour, dirt and other fragments can get under the nail, causing it to have a dark appearance. Feet are especially susceptible to fungal infections because socks and shoes create a warm and moist environment — a fungus’s dream! Over-the-counter treatments are typically ineffective against fungal toenails since they don’t penetrate the actual fungus living under the toenail. That’s why, if your black nail is caused by a fungus, a chiropodist’s visit is needed to get proper and effective anti-fungal treatment.

4. Underlying Conditions

If you are noticing a black spot under your toenail, it could be a symptom of an illness in another part of your body. For instance, diabetes can cause black toenails due to the decreased circulation associated with the disease. Other illnesses that can cause darkened nails include kidney disease, anemia and heart disease. If you notice a black toenail and are currently living with one of these conditions, or think you might be, speak to your family doctor.

5. Melanoma

It is very rare, but the dark dot under your toenail could be melanoma. This form of skin cancer is highly aggressive, and causes dark, irregular looking patches on the skin. It is possible for melanoma to form below a nail, giving the appearance of a black toenail. If you are concerned your dark spot could be melanoma, schedule an appointment with your family doctor as soon as possible.

What Should I Do If I Get a Black Toenail?

Black toenails are surprisingly common, and normally, nothing to worry about. To prevent the usual causes of black spots on your toenails, remember to wear well-fitted shoes, keep your nails cut short and feet dry. In rare circumstances, black dots under your nail can be a sign of something serious. If your black toenail is not improving or you are concerned, make an appointment to speak to a chiropodist.

Confused why your toenail has gone dark? We have the answer!

A black toenail can be scary to find! Here at Feet First Clinic, we’re here to help you discover the root of the problem and make sure your toenails stay healthy in the future. Call us even to ask about a quick question and we’d be happy to point you in the right direction!

Call us at 416-769-3338 or Book Your Assessment Today!

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Carolina Charles

Patient Relation Coordinator (She/Her)

If you’ve been to the clinic before, chances are you had the pleasure of meeting Carolina! Carolina’s daily goal is going above and beyond to make sure patients are always completely satisfied. Having worked in the podiatry industry for 22 years, Carolina brings a wealth of knowledge pertaining to client service, insurance policies, and procedures.​ She steers the ship to make sure everything runs smoothly on the daily. Carolina is known for spicing up every outfit with her signature costume jewellery.