A cap for a medication container may include: at least one pressure sensor； an air supplying unit； and a controller. The controller may be configured to: receive a first air pressure measurement form inside the medication container, form the at least one pressure sensor； control the air supply unit to supply air at a predetermined pressure for a predetermined amount of time； receive a second air pressure measurement from inside the medication container, form the at least one pressure sensor； and perform an output operation using the first and second air pressure measurements.
