The most common nail abnormalities seen in subacute bacterial endocarditis (SBE) are subungual splinter hemorrhages, which result from disruption of the fine capillaries along the subungual dermal ridges. Other cutaneous findings of SBE include petechiae, Osler nodes, Janeway lesions, and Roth spots. Finger clubbing may occur as a late sign.

Bacterial endocarditis with a short course (less than 2 weeks before therapy) and abrupt onset is called acute bacterial endocarditis (ABE). Endocarditis evolving over several weeks or months is called subacute bacterial endocarditis (SBE). Streptococci are the cause of the majority of valvular endocarditis, and staphylococci and streptococci cause approximately one-third of late prosthetic valve endocarditis. Staphylococci cause a majority of valvular endocarditis in IV drug abusers. Endocarditis may be "culture-negative" when caused by Candida or Aspergillus. The patient may appear acutely ill or chronically ill and wasted. Most patients will have a cardiac murmur at some stage, although in early stages, perhaps 15% will have no murmur, especially with right-sided ABE. A change in the heart murmur is not common. Splenomegaly is seen in approximately 30–50% of patients.

The number of patients with prior cardiac surgery, immunosuppression, and drug abuse has increased. Mitral valve prolapse is a risk factor only when associated with a precordial systolic murmur. In recent years, an increase in endocarditis in males and elderly patients; acute endocarditis; and endocarditis caused by gram-negative bacteria, fungi, and miscellaneous microbes has occurred. Tricuspid valvular disease is associated with IV drug abuse. Veterinarians in California have been shown to be at risk for Q fever endocarditis.