Splinter hemorrhages are tiny blood spots that appear underneath the nail. They look like splinters and occur when tiny blood vessels (capillaries) along the nail bed are damaged and burst. The nail bed is the skin underneath the nail.
Small amounts of blood from the damaged blood vessel become visible through the nail. The bleeding creates a splinter-like line in the direction of nail growth. Splinter hemorrhages can occur on your toenails or fingernails.
The primary symptom of a splinter hemorrhage is a small amount of bleeding underneath a nail. You may notice a dark red or brown line along your nail groove. The dark streak closely resembles a splinter.
A splinter hemorrhage doesn’t usually cause physical pain. In fact, you may not immediately notice the hemorrhage. The exception is when a splinter hemorrhage occurs from an injury, such as hitting your toe or finger. In this case, you may have swelling, inflammation, and pain along with a small amount of blood.
Splinter hemorrhages can develop after an injury or trauma to a fingernail or toenail. Stubbing a toe or injuring a finger can damage blood vessels along the nail bed on the affected digit and trigger bleeding underneath the nail.
Splinter hemorrhages caused by injury aren’t a reason for concern. The nail will clear up as the injury heals. But sometimes a splinter hemorrhage indicates an underlying disease or disorder.
If you didn’t injure your toe or finger, the hemorrhage may result from conditions that can damage blood vessels. Underlying conditions may include:
- Bacterial endocarditis: Bacterial in the blood stream travels to the heart valve.
- Vasculitis: Blood vessel damage caused by inflammation.
- Systemic diseases: These cause inflammation in blood vessels, such as rheumatoid arthritis, nail psoriasis, lupus, scleroderma, peptic ulcer, malignancies.
- Fungal infection of the nail: Infections can trigger thinning of the nail bed and possible blood vessel damage.
- Diabetes: High glucose levels can damage blood vessels.
- Raynaud’s disease: Toes and fingers become oversensitive to coldness, which can damage capillaries in the nail bed.
- Cholesterol: Accumulation of this substance in the blood vessels of the fingernails can result in damage.
Splinter hemorrhages can also occur as a side effect of certain medications, such as nonsteroidal anti-inflammatory drugs. These medications can cause bleeding when taken in high doses.
If you experience minor bleeding from a splinter hemorrhage caused by an injury, there’s no reason to see a doctor. On the other hand, if a splinter hemorrhage occurs for an unknown reason, or if you have bleeding in more than one nail, see a doctor for further evaluation.
Your doctor may ask about your medical history and family medical history. Laboratory tests used to determine the cause of splinter hemorrhages include:
- blood culture (detects bacteria or fungi in your blood)
- complete blood count
- erythrocyte sedimentation rate (detects inflammation in your body)
Sometimes a hemorrhage under the nail is a sign of melanoma, a type of cancer. If your doctor suspects a malignancy, they’ll recommend a biopsy to determine whether the dark spot is cancerous or benign.
Treatments depend on the underlying cause.
Treatments for splinter hemorrhages caused by trauma
No treatment is necessary for splinter hemorrhages caused by trauma. Depending on the severity of the injury, the hemorrhage may clear up within a couple of days or slowly disappear as your nail grows out. Because nails grow at a slow pace, it may take several months for the splinter-like mark to completely disappear.
If you have pain following an injury to your fingernail or toenail, apply a cold compress to the area to reduce swelling and inflammation, or take over-the-counter pain medication as directed.
Treatments for other causes
Splinter hemorrhages caused by a disease or disorder may clear up after treating or curing the underlying cause.
Treatment for these types of hemorrhages vary. For example, your doctor may prescribe medication or recommend an over-the-counter antifungal for splinter hemorrhages caused by a fungal infection. Or you may receive a prescription corticosteroid or immunosuppressant if the underlying cause is a systemic disease like rheumatoid arthritis or nail psoriasis.
If testing determines that you have bacterial endocarditis, your doctor may prescribe an antibiotic or recommend surgery to repair your heart valves.
When splinter hemorrhages are a side effect of medication, the hemorrhage may disappear once you stop taking the medication.
The outlook for splinter hemorrhages is often positive. When caused by trauma, the nail slowly heals and clears up without medical treatment.
For the best possible outcome for hemorrhages caused by an underlying disease or disorder, listen to your doctor’s recommendations. This may include discontinuing certain medications, as well as taking medications as directed.