Increase your stamina first or else will have to undergo certain blood tests.
One can increase your stamina by including a well-balanced diet
by adding low-fat products, plenty of fruits and vegetables and lean meat. So,increase intake of healthy food (food having anti-oxidants like green vegetables, nuts, salads, fruits, fish, green tea; food rich in calcium like milk & milk products; flaxseeds, poppyseeds), avoid alcohol & smoking
, drink lots of water (10-12 glasses per day), take sufficient sleep (6-9hrs per day), avoid taking unnecessary stress
/ tension, sports like football, basketball and all other sprinting games will help strengthen your heart so that more oxygen reaches all parts of your body, include cardiovascular exercises like running, swimming, jumping etc. and exercise daily for 30-45 minutes (brisk walk is the best exercise to increase the circulation of the whole body), later you can increase the duration as per your stamina.
(Do the above slowly and gradually).
Take Schwabe's Alfaalfa Tonic and Five Phos./ thrice a day daily for 4 weeks.