Q: My 4-year-old son is 82 cm tall and weighs only 22 pounds. He has a good appetite and takes a diet rich in calories. His blood tests report that everything is normal. He is an active and happy child. When he was just 5 months old, he had severe constipation but no other problem has occurred to him after that. Is he underweight due to some hormonal imbalance?

A:Your child has an above average height but is underweight. According to you he is active and has a good appetite. He needs a good paediatric evaluation to rule out some disorders that can be occult and still hamper weight gain. These include heart disease, renal failure, celiac disease, childhood diabetes etc. Once these disorders have been excluded, all we need to do is keep a 6 monthly weight and height record. Ideally, these should be plotted on a growth chart. As long as the rate of weight and height gain is normal, we need not worry.