An evaluation of bacterial endocarditis begins with a medical history and physical examination.

Physical findings in someone with bacterial endocarditis may include:

• Heart murmur
• Enlargement of spleen
• Rashes that look like broken blood vessels in the skin or bruises:
• Janeway lesions
• Splinter hemorrhages
• Irregular heartbeat (cardiac arrhythmia)
• Conjunctival hemorrhage
• Neck vein distention
• Pallor

Test are required to confirm the diagnosis of bacterial endocarditis.

Tests that may be used to evaluate bacterial endocarditis include:

• Pulse oximetry
• Blood electrolytes
• Blood cultures
• Antistreptolysin O titers (ASO titers): used to detect a streptococcal infection.
• Erythrocyte sedimentation rate
• Complete blood count
• Echocardiogram:
• An effective and noninvasive diagnostic procedure for endocarditis.
• It can directly reveal the presence of vegetations on the heart valves in up to 80% of cases of primary endocarditis infection.
• Chest x-ray