Black toenails can result from a trauma, a fungal infection, or pigmentation changes over time. More serious causes include heart disease or melanoma. Changing shoes may resolve it, but some people may need medical treatment.
The best way to tell the difference between nail trauma and a fungal infection is to keep an eye on the marks for a while. Marks from a nail injury will eventually fade or grow out as the nail does. Spots and streaks from a fungal infection, however, will gradually change shape and grow.
Bruised toenails tend to be darker in color than fungal toenails. While fungal infections tend to be yellow to medium brown, bruised toenails tend to be red or purplish before becoming dark brown, or sometimes even black.
The body responds to trauma in a typical way. It attempts to protect itself and so it creates layers upon layers of nail. Therefore, the nail becomes thicker. Often, the nail appearance can mistaken for a fungal infection.
A subungual hematoma is usually caused by trauma from dropping something heavy on your foot or from frequent rubbing or friction against a shoe. It occurs when the blood vessels break open under the nail, causing blood to pool. Your toenail may look like a black, blue or purple bruise.
Symptoms. A subungual hematoma appears dark red under the nail. The finger or toe is painful and may throb. Other nail trauma also may be painful, and the nail can split, crack, or lift away from the nail bed.
Several health conditions can affect the appearance of your toenails and may be mistaken for toenail fungus. Psoriasis Psoriasis can cause red, scaly patches on the skin. More than half of people with skin psoriasis also have it on their nails.
It begins as a white or yellow-brown spot under the tip of your fingernail or toenail. As the fungal infection goes deeper, the nail may discolor, thicken and crumble at the edge. Nail fungus can affect several nails. If your condition is mild and not bothering you, you may not need treatment.
Black toenails can be caused by underlying medical conditions. Apparently unrelated conditions, such as diabetes, heart disease, kidney disease, and anemia, can also cause discolored toenails. So don't ignore any discolored toenail that doesn't disappear on its own, and relatively promptly.
Black Toenail: Common Causes
If your toenail turns black, it's most likely a bruise under the nail, technically called a subungual hematoma. You can get it from stubbing a toe or from footwear that cram your feet into the front of the shoe.
Signs of a toenail fungal infection
Nails can be brown, black, white, or yellow. Usually a small area changes color at first and it slowly spreads.
It is especially important to see a doctor for the following: You had blunt trauma to the toenail, such as a heavy object dropped on the toe, which may also include a broken toe bone that needs treatment or a cut that needs stitches. There is severe swelling, pain, or redness of the toe.
You can get it if your nails are frequently moist or you often wear sweaty socks and shoes. The fungi usually infect a nail by getting into a: Small cut in the skin surrounding your nail. Crack in your nail.
The most frequent reason for discolored toenails is nail fungus, which is challenging to treat but rarely a serious source of discomfort. Aside from injuries, most conditions that cause toenails to change color may require treatment from a doctor.
Subungual melanoma often starts as a brown or black streak under a toenail or fingernail. A person may mistake it for a bruise. The main symptoms of subungual melanoma include: brown or black streaks in the nail without any known injury.
Splinter hemorrhages appear as small black or deep-red lines and are caused by injuries to the small blood vessels under the nail beds. They usually heal on their own within a few days. If a person has multiple splinter hemorrhages across several different nails, it could indicate an underlying condition.
When checking your nails for melanoma, dermatologists recommend looking for the following changes: A dark streak. This may look like a brown or black band in the nail — often on the thumb or big toe of your dominant hand or foot. However, this dark streak can show up on any nail.
In mild cases, the black toenail will grow out naturally over time without treatment. In severe cases, such as when the nail begins to detach from the nail bed, a person should seek medical treatment.
Black toenails will typically go away on their own, but it can take several months. The condition will diminish once new tissue grows completely under the toenail itself. There are several ways to prevent a black toenail from happening in the first place.
The trapped blood will eventually be reabsorbed, and the dark mark will disappear. This can take 2–3 months for a fingernail, and up to 9 months for a toenail. If there is severe damage to the nail bed, the nail may be malformed or cracked when it grows back.