Splinter hemorrhages appear as narrow, red to reddish-brown lines of blood beneath the nails. They run in the direction of nail growth and are named splinter hemorrhages because they look like a splinter beneath the fingernail. The hemorrhages may be caused by tiny clots that damage the small capillaries under the nails.

Splinter hemorrhages are associated with infection of the heart valves (endocarditis ) and may be caused by vessel damage from swelling of the blood vessels (vasculitis ) or tiny clots that damage the small capillaries (microemboli).

• Trauma to the nail
• Subacute or acute bacterial endocarditis

There is no specific care for splinter hemorrhages. Follow your health care provider's instructions for treating endocarditis.

Contact your health care provider if:

• You notice splinter hemorrhages and you haven't had any recent trauma to the nail

Your doctor will examine you to determine the cause of the splinter hemorrhages. Your doctor may ask you the following medical history questions:

• When did you first notice this?
• Have you had trauma to the nails recently?
• Do you have a known diagnosis of endocarditis, or has your health care provider suspected endocarditis?
• What other symptoms do you have, such as shortness of breath, fever, general ill feeling, or muscle aches?

Physical examination may include special attention to the heart and blood circulation systems.

Laboratory studies may include:

• Blood cultures
• CBC
• ESR

In addition, your health care provider may order:

• Chest x-ray
• Echocardiogram
• ECG

After seeing your health care provider:

You may want to add a diagnosis related to splinter hemorrhages to your personal medical record.

Seidel HM, Ball JW, Dains JE, Benedict GW. Mosby's Guide to Physical Examination. 6th ed. Mosby: Philadelphia, Pa; 2007.

Holzberg M. Common nail disorders. Dermatol Clin. 2006;24:349-354.