Introduction
In most cases, bruising under the nail develops as a result of an accident, such as a blow with a hammer or trapping a finger in a door. As a result of the pressure, the small vessels under the nail begin to contract and tear open. The escaping blood accumulates under the nail, so that a bluish to black discoloration becomes visible.
Causes of bruising under the nail
The causes for a bruise under the nail are manifold. Most often the injury is caused by external trauma or violence. Again, various mechanisms are conceivable: On the one hand, a hard impact of the fingers or toes can lead to the formation of a bruise under the nail.
On the other hand, a blow or bruise can cause the formation of bruises. However, an acute event does not always have to lead to a bruise under the nail. Sometimes the wrong footwear is enough to cause bruising on the toenail.
The right footwear is therefore very important, especially during sports. Shoes that are too tight and small pinch the toes and promote the occurrence of painful bruising. Repeated & continuous stress constricts the toes and exposes them to strong pressure, so that eventually bruising can occur.
However, even very sturdy footwear, such as work shoes or hiking boots, can cause bruising under the nails when breaking in. If, however, the bruise cannot be explained by an injury or shoes that are too tight, another possible cause is black skin cancer (melanoma). It typically presents itself as an elongated brown to black coloured line under the nail.
The appearance of this phenomenon is also called the Hutchinson sign in medicine. If the stain does not disappear or fades and exceeds the limits of the nail, it should be shown to a dermatologist immediately. The absence of pain, in combination with the other signs already mentioned, is also suspicious of black skin cancer.
Symptoms of bruising under the nail
A bruise under the nail is particularly painful immediately after an injury. It is a pressure pain, which is strongest in the first days. A pulsating feeling in the affected nail is also typical.
A large bruise under the nail often causes severe pain, as the nail is lifted from the nail bed by the blood that accumulates under it. This in turn tries to hold and fix the nail. The resulting pressure leads to a pulling, throbbing pain.
The discoloration of the stain varies from black, brown to blue. After a few days the bruise increasingly fades by itself. As a sign of the healing of a bruise under the nail, other colour compositions develop in the course of time.
Depending on the type of injury, damage and bruising may be visible in the surrounding tissue. A very large bruise can cause the nail plate to detach and lift. In the worst case, the nail will then fall off.
In the case of a black skin cancer, which can also form under the nail and resemble a bruise to confuse, the pain is absent. It neither changes colour nor hurts when pressure is applied. There is also no detachment of the nail plate.
The discolouration of black skin cancer does not fade or disappear by itself. The pain associated with a bruise under the nail can vary greatly. They depend on the cause and above all on the size and also the spread of the bruise.
Only slight bumps or injuries usually cause slight pain, which is triggered by pressure. They have a pulling and stabbing character, but are usually not very long lasting and can be easily limited by cooling measures. After one or two days, the pain can in many cases only be triggered by external pressure.
If it is a bruise resulting from a major injury or severe bruising, the pain associated with this accident is much more intense. If a lot of blood accumulates under the nail, a sudden, stabbing, throbbing pain develops, which increases in intensity. This can be explained by the fact that the bruise causes the nail to be lifted from the nail bed, thus exerting strong pressure.
The pain only subsides after the pressure is relieved and the congested blood can drain away. As a rule, the nail can then continue to hurt slightly under pressure for about 4 – 6 weeks. The pain can also be caused by surrounding soft tissue injuries or even injuries to the bone that occurred during the accident.
Therefore, the pain can be more prolonged with more severe injuries and painkillers may have to be administered to provide relief. The classic symptom of a bruise under the nail is pain. In addition, in most cases there is swelling and reddening of the affected finger or toe end.
The nail usually changes its colour to blue to violet relatively quickly due to the blood running under the nail. In the further course of the disease the bruise turns black due to healing processes. Depending on the extent of the bruise, the nail plate lifts.
This can lead to a complete detachment of the nail in case of particularly voluminous and space-consuming bruises. There is also the danger that other structures such as the finger or hand bones, but also tendons or muscles are affected. Such further injuries can occur especially in the case of impact trauma or falls.
For this reason, it is recommended that the doctor take a detailed medical history and perform a functional examination of the affected fingers and toes to rule out fractures or sprains. As a rule, a bruise under the nail grows out over time. Depending on the nature of the nail and the duration of growth, this process can take several weeks.
In the case of particularly severe injuries or bruises, however, it can also happen that the bruise does not grow out, but the complete nail plate detaches from the nail bed and falls off. In most cases the nail only partially loosens and loosens further in the course of the bruise, so that it then finally falls off. Once the nail has loosened, care must be taken to ensure that no bacteria or germs enter the wound and cause infections.
In addition, the wound should be kept as dry as possible, otherwise the risk of developing a fungal disease of the nail bed is very high. In this case it is essential to consult a doctor who can clean the wound and prevent possible infections with the help of ointments and bandages. The fallen out nail grows back again. In order to support the healing process, regular professional nail care should be carried out. In this way, complications and deformations in the course of growth can be prevented as far as possible.
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