The Carey Coombs Murmur occurs during acute rheumatic fever. Mitral valvulitis can occur causing thickening of the leaflets. A murmur is created by increased blood flow across the thickened mitral valve. This can be distinguished from rheumatic mitral valve stenosis by the absence of an opening snap. The murmur is described as a mid diastolic murmur heard at the mitral listening post with the bell of the stethoscope with the patient in the left lateral decubitus position at end expiration. As the rheumatic valvulitis resolves, the murmur disappears.