Smoking in itself will not affect Medicals, but it's adverse effects on health will, depending on how bad the damage is. In some cases there will/ may be no damage at all. However, It is a well known medical fact that Smoking is hard on the heart. It is also a fact that can not be denied that tobacco use plays a role in a multitude of diseases. Cigarette smoke contains over 4,000 chemical compounds; 200 of which are known to be poisonous, and upwards of 60 have been identified as carcinogens.
Viewed in that light, it's no wonder that the effects of smoking could be negative and are destructive.
Good Luck.
BobbyB