You have suffered pulmonary TB in past. Your chest X – ray is showing old scar of tuberculous lesion in the form of fibrosis/scarring in right peri-apical areas of your lung. Your lung is otherwise normal with no active lesion. Take nutritious food rich in vitamins and protein such as egg, meat, green vegetables, cheese etc. Immediately consult your doctor if you have fever, cough, blood in sputum, chest pain and night sweats. Consult a private or government doctor for issuing fitness certificate he/she might check your X – ray or might recommend additional tests. Otherwise you are fit. Underweight is not always due to disease. There are various causes of underweight like inadequate food intake, prolonged meal time gaps, and increased physical activity weight increasing food intake. Other reasons are mostly medical conditions like TB, cancer, malabsorption, and hyperthyroidism. Also calculate your BMI. If it is in normal range then there is no need to gain weight. Body mass index (BMI) below 18.5 is underweight. BMI is calculated by formula BMI = Weight in Kilograms / (height in meters x height in meters). If you want to gain weight then gradual weight gain advisable. Natural ways of gaining weight is advisable. Advice 1. Adopt natural ways of gaining weight 2. Start workout in gym at least for half an hour for 4 – 5 days in a week regularly 3. Take natural high protein like egg, soya bean, pulses, meat, and milk. Choose food with nutritional calories like potato, banana and dry fruits 4. Drink 3 – 4 liters of water daily 5. Avoid excess intake tea and coffee after meal as they contain tannin which hinders absorption of minerals like iron Thanks