Splinter Hemorrhages: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Splinter Hemorrhages?
A primary care doctor can check splinter hemorrhages and look for the cause. A dermatologist, a doctor who treats skin and nails, can also examine the nails closely. If a heart infection is suspected, a cardiologist, a doctor who treats heart problems, may help. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What are splinter hemorrhages?
Splinter hemorrhages are small areas of bleeding under the fingernails or toenails. A hemorrhage is another word for bleeding. They look like thin, red to reddish-brown lines of blood under the nail. The lines run in the same direction as the nail grows.
They get their name because they look like a splinter under the nail. They are also called fingernail hemorrhage. Researchers call them a common nail problem. They can be hard to tell apart from other nail problems, including a cancer called melanoma that can grow under the nail.
Symptoms
The main sign is the mark under the nail. Look for:
- Thin lines of blood under a fingernail or toenail.
- A red to reddish-brown color.
- Lines that run in the same direction as nail growth.
When a heart valve infection is the cause, other symptoms usually show up first. These can include fever, a general ill feeling, and muscle aches. The nail marks most often appear late in that infection.
Causes and who gets it
Splinter hemorrhages happen when tiny blood clots damage the small blood vessels, called capillaries, under the nail. Swelling of the blood vessels, called vasculitis, can also cause the damage. Both of these can occur with endocarditis, an infection of the heart valves.
MedlinePlus lists two causes. One is bacterial endocarditis. The other is an injury to the nail.
How doctors diagnose it
Your provider will look at your nails and ask questions. These may include when you first noticed the marks and whether you hurt the nail. You may also be asked about other symptoms, such as fever, a general ill feeling, or muscle aches.
The exam may focus on your heart and blood flow. Tests may include blood cultures, which look for germs in the blood, a complete blood count, and a blood test called ESR. Your provider may also order a chest x-ray, an ECG, which records the heart's rhythm, or an echocardiogram, which is an ultrasound of the heart.
Doctors can also use dermoscopy, a close-up look at the nail with a special tool. It can help tell splinter hemorrhages from other nail problems such as melanoma.
Treatment
There is no specific care for splinter hemorrhages. If endocarditis is the cause, follow your provider's instructions for treating it.
Your provider will look for the cause of the marks. A nail injury is one possible cause, and endocarditis is another.
When to see a doctor
Contact your provider if you see splinter hemorrhages and you have not recently hurt the nail. Also tell your provider about fever, a general ill feeling, or muscle aches along with the nail marks.
Call 911 or go to the emergency room if you have trouble breathing, chest pain, fainting, or confusion or other sudden changes in how you act.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either kind of doctor can look at the nails, ask about injuries and other symptoms, and order basic tests. They can also refer you to a skin or heart specialist when needed.
Common questions
Are splinter hemorrhages dangerous?
Not always, but they can point to a serious problem such as a heart valve infection. An injury to the nail is one possible cause. If you have not hurt the nail, contact your provider.
What do splinter hemorrhages look like?
They look like thin, red to reddish-brown lines of blood under the nail. The lines run in the same direction as nail growth. They can appear under fingernails or toenails.
Do splinter hemorrhages need treatment?
Usually not for the marks themselves, because there is no specific care for them. If a heart valve infection is the cause, that infection needs treatment. Your provider can tell you which applies.
Can splinter hemorrhages be a sign of a heart problem?
Yes, they can occur with endocarditis, an infection of the heart valves. They most often appear late in that illness. Other symptoms usually bring people to a provider first.
Can an injury cause splinter hemorrhages?
Yes, an injury to the nail can cause them. MedlinePlus also lists bacterial endocarditis, an infection of the heart valves, as a cause.
Sources
- MedlinePlus - Splinter hemorrhages
- Indian Journal of Dermatology (PubMed Central) - Clinical Observation and Follow-Up of Subungual Splinter Hemorrhages of Toenails in Chinese Adults
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
