My baby Z is 4 months old. I observed his hair is falling. I wonder if it is normal or not?

Hi... That us strange fir a 4 month baby to have a hair fall. I think you should consult with your PD but at the same time check his scalp for any infection or dermatitis or may be can check the shampoo you are using for hair wash. Ut may be containing chemicals that might be acting too hard on his skin.