I have a 16 month old baby boy but he looks very small for his age snd has a high belly is something wrong there?

Probably: If your son is following his growth curve, then he is probably growing appropriately. Everyone has different body types. Some of us have short chests and long legs or long chests and short legs. If you are concerned that there is something wrong with your son, then i would discuss this with your son's doctor.

Check growth charts: At 16 months of age, his last check up would have been at 12 months. His doctor can recheck the growth since then, do an exam, check the belly, and review the growth chart. The next check up is at 18 months, and the doctor can re-examine and measure the height and weight again. A baby's size is usually determined by the size of the parents, and their familial/genetic/racial backgrounds.