An apparatus for detecting a biological data of a target patient from an attachable sensor attached to the target patient includes a circuit. The circuit obtains a first piece of biological data and patient-state data of the target patient. The circuit determine an activity state of the target patient on the basis of the patient-state data. When the activity state is first state, the circuit detects an abnormality in the target patient on the basis of a first normal value range, in the first state, of a physiological indicator indicated by the first piece of biological data and the first piece of biological data. When the activity state is second state, the circuit detects an abnormality on the basis of a second normal value range, in the second state, of the physiological indicator indicated by the first piece of biological data and the first piece of biological data.
