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Black nail

The black nail is a disorder characterized by the accumulation of blood under the nail. One of the most common causes is an injury to the finger, such as a fall on it from a heavy target. Thus, as a result of the injury, the nail turns, totally or partially, black or purple.

What is the black nail?

The black nail, whose technical name is subungual hematoma, is a hematoma located under the nail . In other words, it is a bruise that instead of being on the skin is located under the nail.

Although the causes that give rise to this condition are very varied, in a high percentage of cases the black nail occurs as a consequence of a strong impact on it or due to microtrauma that are frequently repeated. However, it can also occur without pain or warning.

Black toenail is especially common among long-distance runners . In this type of sports, the feet are subjected to a continuous stomping session for a long period of time; small impacts that the fingers must absorb and that can give rise to what is known as a black nail.

Possible causes

Here are the main causes for this condition.


The onychomycosis is an infection that is caused by fungi in toenails. In the vast majority of cases, the infection originates in the big toe, and if proper treatment is not given, it can spread to the rest of the nails.

One of the most noticeable signs of onychomycosis is the change in color and shape of the affected nail, which turns black. In general, it does not cause great discomfort at first, so those who suffer from it do not go to the doctor soon. Thus, the risk that the infection completely invades the nail is high.

Malignant melanoma

Although not very common, a malignant melanogma can also lead to black nail. It is a malignant tumor that is derived from melanocytes , the cells responsible for the production of pigment in the skin.

Wrong footwear

Black toenail can also be caused by wearing the wrong footwear . If this is one size smaller, the toes are compressed and are subjected to continuous pounding on the inside. Similarly, if the shoe is one size larger, there is repeated movement due to lack of grip.

The use of narrow-toed shoes is also not recommended as it exerts great pressure due to the friction of the shoe against the fingers.

Long or misshapen nails

Although long or deformed nails are not a direct cause of black nail, they do significantly increase the risk of suffering from this disorder. That is why special attention should be paid to the care of the toenails.

By direct hit

One of the most recurring causes of black toenail is an injury from a blow of great intensity , such as a heavy object falling on the foot. In these types of situations, blood vessels break, accumulating blood under the nail.


Repeated pressure over a long period of time on the toes can lead to what is called repetitive trauma, thereby causing blood clots to form under the nail.

Who is affected by the black nail?

One of the population groups most affected by this disorder are long-distance runners . However, this condition can also affect other athletes, such as soccer players. They hit the ball hundreds of times during the game, thus causing repeated microtraumas, which are especially localized to the nails as the ball is hit with the toe of the boot.

Also in skiers since in practice this sport is based on the descent down slopes with a great unevenness, in which the body weight falls on the tips of the fingers. Thus, the nails are the most affected.

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Of course it is not an exclusive disorder of the sports field. All those people who use inappropriate footwear or who do not maintain good hygiene of their feet have a high probability of suffering from it.

Symptoms of black nail

As its name suggests, the most obvious sign of this disorder is the black color of the affected nail. However, like a bruise , the range of colors is very wide; it can be from a very light yellowish tone to the darkest black.

In addition to the color change of the nail, other symptoms occur, for example pain . Those who suffer from this disorder feel intense and throbbing pain in the area, which becomes greater and greater as the injury progresses.

Although the black nail is not a serious condition from the medical point of view, it is necessary to apply the appropriate treatment as soon as possible. Failure to do so may result in inability to support the foot due to the pain of doing so.

Recommended treatment

In case of observing a hematoma located under the toenail, it is important to see a doctor as soon as possible. And it is that the time factor plays an essential role in any type of clinical disorder.

The doctor first takes a medical history of the patient, asking him about the symptoms, as well as if he practices any type of sport or if he has recently suffered a stroke.

If the black nail has originated in the last 48 hours and the body has not begun to reabsorb the blood clot, the most common treatment is to drain the clot. The doctor proceeds to make a small incision in the nail, through which the accumulated blood in the area is drained.

If it has been too long since the bruise has appeared under the nail, there is no possible medical treatment. You can only wait for the nail to come off on its own with the passage of time.

How to prevent black nail

There are a number of measures to take into account to prevent this disorder as much as possible.

  • Nails: as we have pointed out, one of the main risk factors is long or deformed nails. That is why it is so important to keep your nails trimmed, always making a straight cut.
  • Socks: in the same way that the footwear adapts to each activity, the socks must also be different. For example, when practicing sports, it is recommended to opt for seamless socks to avoid chafing.
  • Footwear: to avoid black nail it is essential to choose the right footwear. To check that the size is correct, it is best to try on your shoes first thing in the day.

Home remedies for black nail

Finally, we want to point out a series of home remedies that are very effective for black nail. It is worth noting that they work when the nail has suffered a blow and you want to avoid the formation of a bruise under the nail.

  • Chamomile: chamomile has great anti-inflammatory properties, making it a highly recommended home remedy to avoid this disorder after an intense blow. It is enough to make an infusion of chamomile and when it is warm, introduce the affected finger. Helps reduce both inflammation and pain.
  • Salt: another home remedy is to place the affected nail in a container of warm water with sea salt. It is very effective in reducing inflammation and preventing the nail from turning black.


In some cases the black nail is a painless disorder. However, as the pressure generated by the accumulated blood under the nail increases, the pain can be severe. Thus, at the slightest symptom it is recommended to go to the doctor as soon as possible.

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Hello Readers, I am Nikki Bella a Psychology student. I have always been concerned about human behavior and the mental processes that lead us to act and think the way we do. My collaboration as an editor in the psychology area of ​​Well Being Pole has allowed me to investigate further and expand my knowledge in the field of mental health; I have also acquired great knowledge about physical health and well-being, two fundamental bases that are directly related and are part of all mental health.

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