Hello, I'm Dr. Robert Eitches, here for About.com.An inhaler works by giving medication directly to the airways. This way you can give concentrated medication to your lungs without giving medication to the rest of your body. The medications employed are either topical steroids to reduce inflammation over the course of a couple of days or they are bronchodilators that more immediately reduce bronchospasm.By delivering the medication directly to the airway, a much smaller dosage is needed than if it were used orally, so they have less toxicity and long-term side effects. They do need proper coordination between spraying and inhaling to get the best results, so if they seem ineffective, you may be using a poor technique, breathing in too soon or too late.I'm Dr. Robert Eitches for About.com. Thanks for watching.