Why do i get a stomach ache while using asthma medication?

Depends on the med: A person can get stomache aches from various medicines, not just asthma meds. He can bring all his meds to his doctor to plan a way to figure out which one(s) is causing the stomach ache. Prednisone can be strong on the stomach lining and cause tummy aches, so a person taking Prednisone for asthma can have stomach symptoms. Also, tummy aches can occur just "coincidentally" with taking medications.

Upset stomach: Could be improper technique or an adverse reaction to that particular medication (if you are using an inhaler). If you are using singulair (montelukast) or accolate, then it might be a simple adverse reaction to the medication. Asthma is deadly, so controller therapy is essential. See your asthma specialist to make sure u r doing the inhaler right or switch to a different controller med.