My 1year old has been diagnosed with a heart murmur. can it make him poorly, affect sleep and his mood?

Hard to generalize: A heart murmur is relatively common and most are simple with no effect on anything in life.In years as a pediatrician I was likely to heart one at least once on every kid if I listened often enough.You need to clarify the origin of the murmur with the kids doc. You don't need to loose sleep over this if it is a common benign murmur.