Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice.
People do have different weights and heights, and there is a normal range. What we find out as BMI, as weight according to height, normal BMI is between 18 and 25,yours is aboutt 22 rather ideal , which is pretty normal and you should be happy. So if you are otherwise normal , you should just enjoy that you are not obese
. Still if you want to gain some weight, you need to increase your caloric intake, you can join gym with diets, the best solution is you should talk to a dietitian who would give you a plan where you would take more calories than you consume. However I am repeating ,its normal , and you better not increase it. Yes the only thing you should worry is that if your weight is getting more and more low, or you have any other problem like low hb, or fever
, or fatigue
Hope I have answered your query. Let me know if I can assist you further.