Talk to General Physician on Weakness , Under Weight

Aoa , mjhy weakness bht hy weight b 40 kg hy khati peti b hn daily milkshake b peti diet b achi rakhny ki koshish krti herbal tariqo sy b dkhlia lakin weight gain nai hota mera kindly aisa kia problem ho skta jis main sab kch krny k bad b ap mazeed weak hon? Or ksy weight gain kia jay ya weakness ko ksy thek kia jay bones m b drd hota or even tak k veins m b kichao ajata kindly help krn