Hi, My baby boy birth weight was 3.4kg. and at 5 months hia weight is around 10kg. Its more than the normal range of weight. He takes normal breast feeding in 3-4 hrs. At night he hardly wakes up for feeding. Still he is gaing weight rapidly. Do we need to check his thyroid or conduct blood test?

I'm very worried as he himself cannot balance his weight and he ia lagging behind to achieving his milestones.

Kindly guide.