Springs are allowed to be called medical springs based upon the Standard Methods of Analysis for Mineral Springs if the temperature at the source is 25 degrees or above or the spring water contains any of following ingredients more than the designated amount measured in 1 kg of water.
泉源の温度が摂氏25度以上であるか、温泉1kg中に以下のいずれかの成分が規定以上含まれているかすると、鉱泉分析法指針における療養泉を名乗ることができる。