For increasing wt start ur day with exercise and walk which increase ur metabolism. Don't skip ur breakfast which increase ur appetite. Take high calorie & rich protein In ur diet. Add good fat and nuts in ur diet. Maintain ur diet diary.

hi     yeah dietician  will suggest which foods are in high calories and which foods are high in protien. you have to take more calories in your food . and also protein rich food. with that mild to moderate exercise increase your weight. you have to tell your weight and height so we can calculate and tell .your weight is normal or not and how much you have to gain weight. and there is no medicine to increase weight. you can undergo thyroid function test and routine blood test once.