What Is a Splinter Hemorrhage?

A splinter hemorrhage, sometimes called a fingernail hemorrhage, is a medical condition that only occurs underneath a person's toenails or fingernails. It is a localized area of bleeding that tends to appear in a straight line, traveling in the direction in which the nail grows. While this condition is most often not a cause for alarm, it can sometimes indicate a more serious underlying medical condition. Along with addressing the underlying cause, if there is one, the standard course of treatment is to allow the nail to grow out so that the discoloration gradually disappears.

Often, a patient acquires a splinter hemorrhage when the nail suffers physical trauma, such as an impact injury. Athletes may be at a higher risk of this type of injury, which occurs when the capillaries, or small blood vessels, underneath the nail have been damaged. Rarely, a splinter hemorrhage may be caused by medication. Blood thinners, such as aspirin, as well as other over-the-counter pain relievers may occasionally result in bleeding under a nail.

A splinter hemorrhage may also rarely be caused by an underlying medical condition. Patients who experience recurring hemorrhages may need to be examined by a doctor to rule out a more serious problem. A fungal infection like onychomycosis may contribute to this condition. Nail psoriasis may also be a factor, because it causes the nail to thin, which makes the small blood vessels more vulnerable to injury.

More serious conditions like lupus and Raynaud's disease are also associated with splinter hemorrhages. Microemboli, which are tiny blood clots, and vasculitis, which occurs when the blood vessels are inflamed, have also been linked to this nail condition. Patients with a heart valve infection called endocarditis may occasionally develop bleeding under the nails; however, usually more serious symptoms are noticed first.

When a doctor suspects that a patient has an underlying cause for the abnormal appearance of his nails, tests will likely be done to check for potential problems. It is essential that the patient discloses all other symptoms he has, even if they may seem unrelated. The doctor may order blood tests, such as a complete blood count (CBC) and an erythrocyte sedimentation rate (ESR), which checks for systemic inflammation. Imaging tests like an echocardiogram or a chest x-ray may also be helpful.

There is no specific treatment for the splinter hemorrhage itself. It will eventually disappear as the nail grows out. Patients should avoid irritating the area and prevent further trauma to the nail. Those that have an underlying medical condition will undergo treatment for that diagnosis.