What Happens When Your Fingernail Gets Bruised?
A bruised fingernail, medically known as a subungual hematoma, occurs when blood becomes trapped underneath the nail plate. This common injury usually results from blunt force trauma, such as accidentally dropping a heavy object on your finger or jamming it in a door. The impact damages the tiny blood vessels beneath the nail, causing them to bleed. The trapped blood accumulates, causing noticeable discoloration (black, blue, or purple) and creating pressure that often results in immediate and throbbing pain. The intensity of this pain typically correlates with the amount of blood trapped and the pressure it exerts on the sensitive nail bed.
How Long Does a Bruised Fingernail Take to Heal?
The healing process takes time because a new, healthy nail must grow to replace the injured one. Fingernails typically grow at about 3.5 millimeters per month, meaning it can take four to six months for a new nail to completely replace an old one. The bruised area will gradually move forward with the growing nail until it reaches the tip and can be trimmed away.
Several factors influence this timeline. The severity of the injury, particularly the amount of trapped blood, affects how long discoloration persists. Age also plays a role, as nail growth tends to slow slightly with increasing age. Overall health and nutritional status can also impact the rate of nail growth and healing.
The Healing Journey of Your Fingernail
As a bruised fingernail heals, the initial dark discoloration will slowly change. The black, blue, or purple hue often fades to a reddish-brown or yellowish color as the trapped blood dries and breaks down. This color change signifies the gradual resolution of the hematoma.
Over several weeks to months, the discolored area visibly shifts towards the fingertip as new, unbruised nail grows from the base near the cuticle. In severe cases, pressure from the hematoma can cause the old, damaged nail to lift away from the nail bed. This separation allows the new nail to grow underneath, eventually pushing the old nail completely off. The natural shedding of the old nail is a normal part of the healing process.
Caring for a Bruised Fingernail and When to See a Doctor
Managing a bruised fingernail at home involves simple measures to reduce pain and swelling. Immediately after the injury, applying ice to the affected finger for 15-20 minutes can help minimize swelling. Elevating the hand above heart level can also help reduce throbbing pain. Over-the-counter pain relievers, such as ibuprofen or acetaminophen, can help manage discomfort.
While many bruised fingernails heal without medical intervention, certain situations warrant a doctor’s visit. Seek medical attention if pain is severe and persistent, especially if it does not subside with medication. Signs of infection, such as increasing redness, warmth, swelling around the nail, or pus, also require professional evaluation. If the nail is completely detached, significantly lifted, or if there is an open wound around the nail bed, a doctor should assess the injury. In severe cases, a doctor might perform trephination, making a small hole in the nail to drain trapped blood and relieve pressure.