My boy is 7 months and is height is only 25% and the nurse keep saying my boy will be short.. what can I do to make him grow in height or nothing I can do? I am worried..

That is rather unnecessary from the nurse. Being shorter now doesn't mean he won't be tall when he grows up! To alleviate your concerns I'd say stretch him out daily. I do this to my boy too, but it's a at-least-I-did-something so I wouldn't feel so guilty! Now it's more of a routine as he really enjoys the stretch. Make sure he gets his sleep too as 'they' always say kids grow in their sleep! Otherwise don't worry, the real battle for height has not arrived.