A health condition estimation apparatus 10 includes an obtaining unit 40 and a controller 42. The obtaining unit 40 obtains gas information. The gas information is based on a signal output by a sensor unit in a period in which a first gas is supplied to the sensor unit and a signal output by the sensor unit in a period in which a second gas is supplied to the sensor unit. The sensor unit outputs a signal with a signal value in accordance with the concentration of a specific gas. The first gas and the second gas are different in at least either of obtaining position and obtaining time. A controller 39 generates health information based on the gas information.