If you are getting fatigued easily and feeling faint, and are a heavy smoker in addition, you should get yourself evaluated by a physician, and get some routine investigations done, including a fasting blood sugar and chest x-ray. Smoking
increases the risk of hypertension
, stroke, COPD, lung cancer
and many other disorders. So, do not neglect these early signs and consult a doctor. Even if your test results come out fine, do consider quitting or at least cutting down on smoking.