10 Nail Changes That May Indicate an Underlying Health Issue

9. Red or Brown Streaks - Infection and Vascular Issues

Red or brown streaks beneath the nails, known as splinter hemorrhages, can indicate various conditions ranging from minor trauma to serious systemic infections or vascular disorders requiring immediate medical attention. These linear streaks appear as thin, dark lines running longitudinally under the nail plate and result from bleeding in the nail bed capillaries, which can be caused by trauma, infection, or underlying vascular pathology. While isolated splinter hemorrhages near the nail tips are often benign and related to minor trauma or occupational activities, multiple streaks or those located in the proximal nail bed may indicate more serious conditions such as infective endocarditis, a potentially life-threatening infection of the heart valves. Subacute bacterial endocarditis classically presents with splinter hemorrhages as part of a constellation of findings including fever, heart murmur, and other embolic phenomena, making nail examination an important component of cardiovascular assessment. Other systemic conditions associated with splinter hemorrhages include rheumatoid arthritis, systemic lupus erythematosus, antiphospholipid syndrome, trichinosis, and severe hypertension, reflecting the nail bed's sensitivity to inflammatory and vascular changes. Drug-induced causes include anticoagulant therapy, chemotherapy agents, and certain antibiotics, while occupational or recreational activities involving repetitive finger trauma can also produce characteristic patterns of splinter hemorrhages. The evaluation of splinter hemorrhages requires careful consideration of their location, number, associated symptoms, and patient risk factors, with proximal or multiple lesions warranting comprehensive medical evaluation including blood cultures, echocardiography, and assessment for systemic inflammatory or infectious conditions.