If you are uncertain as to whether or not you are inhaling the medication correctly, try this test:

Prepare the Diskus for inhaling the medication as described earlier.

Place a small piece of a dark-colored cloth over the mouthpiece.

Exhale comfortably.

Seal your lips over the cloth.

Inhale a full, deep breath as described earlier.

Carefully pull back the cloth to observe a small amount of white powder. This is the medication you would have otherwise inhaled.