What Is A Black Toenail?

Whether you would choose black or another colour for your nail polish, if your toenail is suddenly sporting a new hue, it’s wise to consider what may have caused it. The most common cause is often something simple, like you dropped something on your foot, and it was so minor you can’t even remember doing it! However, if you notice any other symptoms, it’s best to consult with a podiatrist for professional advice.

This article explains what a black toenail is, what may cause it, and potential treatment options. For personalised advice, contact our team at Foot Health Clinic today.

What Is a Black Toenail?

A black toenail, or a subungual haematoma, occurs when blood accumulates under a toenail. This accumulation of blood causes the toenail to appear black, brown, or even purple. In most cases, this isn’t a serious condition and you may be able to treat it at home.

As well as discolouration, additional symptoms of black toenails include:

• Pain
• The nail becoming loose or brittle
• Discomfort
• Swelling
• Buising
• The nail separating from the nail bed
• The nail thickening and splitting

In some cases, especially if left untreated, black toenails may become infected. Infected toenails may show symptoms such as:

• Swelling
• Odour
• Discharge
• Redness

While it’s always important to seek medical attention for any changes in your body, such as black toenails, this is especially crucial if you suspect you may have an infection. Ensure you make an appointment with your podiatrist as soon as possible if you notice any of the above.

What Causes Black Toenails?

There are many potential causes of black toenails. If your toenail turns black due to blood collecting underneath it, this may be caused by:

1. Trauma

Whether it was a one-off incident or repetitive trauma, injuring your toe is one of the most common causes of black toenails. This could be stubbing your toe against a piece of furniture, participating in sports that are hard on the toes such as dancing or running, or even wearing improperly fitting shoes. While this may typically be treatable at home, if the haematoma is large or the nail becomes loose, you should consult with a podiatrist to ensure the nail grows back as healthily as possible.

2. Fungal Infections

A fungal infection, or onychomycosis, is often responsible for blackened toenails. Fungal infections often develop if you come into contact with a fungus and you have a crack or cut near the nail. Toenail fungus is most common in people with diabetes, peripheral arterial disease, and other health conditions that impact circulation and blood vessels. People who use public showers, pools, and gyms with bare feet are also susceptible to fungal infections. However, anybody may develop a fungal infection.

3. Runner's Toe

'Runner's toe' is a form of subungual haematoma, and most commonly happens to the second and third toes. This is caused by your toe bumping into or rubbing against your shoe as you move, which is why it's more common in runners. Runners, or anybody else, who wear tight or otherwise ill-fitting footwear are more likely to develop runner's toe, as feet tend to swell during exercise, creating more pressure. Incorrectly fitting footwear also may compress the toes and therefore damage the nail.

4. Ingrown Toenails

Ingrown toenails are where your toenail grows into the skin surrounding the nail bed, rather than away from it. If you have an ingrown toenail, you may be more likely to develop a bacterial infection, which may lead to nail discolouration.

5. An Underlying Medical Condition

Underlying health problems may contribute to black toenails. Some health conditions that may discolour toenails include psoriasis, anemia, heart infections, diabetes, and kidney disease. For people with diabetes, nail discolouration is more likely to appear yellow rather than black, brown, or purple, though blackening may occur. If you have any of these medical conditions, ensure you check your toenails and fingernails regularly and monitor for any changes.

6. Skin Cancer

In rare cases, blackened toenails may occur due to skin cancer, or subungual melanoma. Malignant melanoma may occur anywhere on the body, including the toenails. This serious form of nail discoluration only happens in very rare cases, but as it is a possibility, it's important to consider. It may come with additional symptoms such as nail thickening or swelling, pain, tenderness, bleeding, and discharge. However, skin cancer that affects the toenails may look like a fungal infection or a reaction to repetitive trauma, so ensure you seek medical attention.

Can You Treat Black Toenails?

Treating black toenails largely depends on the cause. However, there are some general instructions you should follow, such as refraining from applying nail polish and ensuring you wear properly fitting shoes. Your podiatrist will give you specific information for your unique situation before working to address both the symptoms and the cause. Treatment options may include:

• Keeping the nail clean by washing it with soap and water and drying it thoroughly afterwards
• Keeping your foot elevated
• Taking over-the-counter oral medication
• Using over-the-counter topical medication in cases of fungal infection
• Wearing shoes with enough space in the toe area to protect the nail
• In rare cases, removing part of the nail or the entire nail

Address Your Black Toenail Today

When a toenail injury bleeds, blood pools and gets trapped under the nail, causing it to take on a dark colour. This may be painful, but in most cases, there are treatment options available. At Foot Health Clinic, we offer a wide range of podiatry services for kids and adults alike, here in Samford Village in Brisbane's north. If you have a black toenail, or are in pain because of an accumulation of blood under your nail, make an appointment with us today.