20 Symptoms of Endocarditis to Look Out For

15. Splinter Hemorrhages

Splinter hemorrhages are thin, red-to-brown lines under the fingernails or toenails, resembling wood splinters. They are caused by small clots that damage capillaries in the nail beds—often linked to infective endocarditis. While not exclusive to this condition, their presence in a febrile patient should trigger suspicion, especially if other signs like petechiae or a murmur coexist. Splinter hemorrhages are painless, transient, and easy to miss. But for the astute clinician, they are a subtle diagnostic clue pointing to a potentially life-threatening cardiac infection beneath the surface.

16. Abdominal Pain or Fullness

Abdominal discomfort in endocarditis often stems from embolic events or organ inflammation—particularly splenomegaly (an enlarged spleen). When emboli from infected heart valves lodge in the spleen or kidneys, they can cause infarcts that present as vague, persistent abdominal pain or fullness. This symptom is especially common in subacute cases and may be accompanied by tenderness in the left upper abdomen. In rare cases, splenic abscesses or rupture can develop. If a patient presents with unexplained abdominal symptoms and systemic infection signs, clinicians should consider imaging to evaluate for organ involvement tied to endocarditis.