A method including obtaining a first motion signal segment sensed by a motion sensor worn on a user's wrist or forearm； detecting the user performed a first action based on the first motion signal segment； obtaining a second motion signal segment sensed by the motion sensor, wherein the second motion signal segment was sensed by the motion sensor after the first motion signal segment； detecting the user performed a second action based on the second motion signal segment and in response to the detection of the first action； determining that a first medication was taken by the user based on the detection of the second action； and, in response to the determination that the first medication was taken by the user, causing presentation of an indication to the user or transmitting an indication to an external device that the first medication was taken by the user.
