Unveiling the Mystery of the Color of My Toenails

This information has been medically reviewed by Dany Paul Baby, MD on June 26, 2022.

While we tend to focus more on our fingernails, it’s important not to overlook changes in our toenails. Discoloration, from blue spots to brown lines, could be a sign of an underlying health condition. Let's dive deeper into what you need to look out for.

If you notice that your toenail has turned black, it's likely a bruise called a subungual hematoma. This condition occurs when your toe is impacted, or as a result of wearing shoes that squeeze the front of the feet. The bruise will usually appear reddish and then progress to shades of purple, dark brown, and finally black when blood accumulates and clots under the nail. It can take up to 9 months or longer for the toenail to grow out completely.

If you have one or more black toenails, and you're positive you haven't sustained any injuries, make sure to check if dye from your shoes has rubbed off on your nails. If that’s not the case, make sure to consult with your doctor for a proper diagnosis, as this could indicate a rare cause of black toenails, which may include malignant melanoma, a serious form of skin cancer, fungal infections, chronic ingrown nails, or other health issues.

Yellow toenails are commonly caused by a fungal infection. This kind of infection is so common that you can treat it with an over-the-counter antifungal cream without going to the doctor. If the nail is thick and yellow, try filing down the nail surface to allow the drug to penetrate deeper layers. However, if at-home treatment doesn't work, it's important to schedule a doctor's appointment to resolve the issue.

When it comes to your toenails, there are certain colors you shouldn't ignore. If you notice a green tint on your nails, it may be a case of chloronychia, or green nail syndrome. This occurs when bacteria thrive in moist environments like hot tubs, sponges, or tightly-worn shoes. Attempting to scrub off the color won't work; instead, seek medical attention from a doctor.

While a blue toenail or spot may not raise any concern after a minor toe injury, an unexplainable blue-hued mole should prompt a trip to the doctor for assessment. Although it's likely harmless, there’s a slim chance that it could be a cellular blue nevus, which can develop into cancer.

If you're expecting a bruise after stubbing your toe, and nothing appears, it may still indicate trauma. The lack of broken blood vessels may result in a white spot or streak on your nail. You might not even be aware you’ve caused an injury, such as from wearing ill-fitting shoes. The white spot won't disappear like a bruise, but it will gradually grow out over time.

On the other hand, if you spot white or powder-like patches on your toenails, it could be a fungal infection known as white superficial onychomycosis. It may spread and make the nail rough and crumbly, so it's crucial to seek medical attention promptly if you suspect this condition.

Another type of fungal infection, proximal subungual onychomycosis, is rare in healthy individuals, but is a greater risk for people with weakened immune systems or HIV. If you notice yellow or white patches that begin at the base of your toenail, near the cuticle, you should immediately consult with a physician.

If you happen to notice red and white stripes on your toenails, it could be an indication of an underlying issue elsewhere in your body. These particular markings, along with V-shaped notches, are indicative of a condition known as Darier disease, which is typically an inherited disease that primarily affects the skin. As a result of this disease, one may develop greasy, warty, and unpleasant-smelling blemishes. 

Melanonychia, on the other hand, is characterized by brown or black coloration of the toenail. Brown coloration often manifests as a line or streak that runs vertically along the nail. Some of the possible causes of Melanonychia are injury, melanoma, inflammatory conditions, fungal infections, or certain medications. Due to the possibility that brown streaks on your toenails may symbolize a more severe underlying condition, it is best to schedule an examination with your medical practitioner.