These murmurs are non-organic and are caused due to the flow rather than any anatomical damage to the heart

These disappear with age

Characteristics

1. Usually systolic
2. Never beyond grade 2
3. No thrill
4. Best heard over pulmonary area
5. No radiation
6. Changes with opposition
7. Otherwise normal heart sounds, normal chest X Ray and ECG

Examples of innocent murmur

Still’s murmur

1. It’s a ejection systolic murmur heard over right sternal border.
2. Due to blood flow across the aortic valve.  
3. Seen in infancy to adolescence

Physiologic systolic ejection murmur

1. Heard best at the left mid to upper sternal border.  
2. Heard with diaphragm of stethoscope

Supraclavicular arterial bruit

1. Heard Above the clavicle.  

Neonatal peripheral pulmonary stenosis(PPS):

1. Heard from Birth to 3-6 months.
2. Heard best at axillae and the back.   

Cervical venous hum

1. It is a Continuous hum.  
2. Best heard over right upper sternal border.