診断 （シンダン） diagnosis, medical examination

診察 （シンサツ） medical examination, checkup, consultation

健診 （ケンシン） health checkup, (general) medical examination, physical examination

受診 （ジュシン） having a medical examination, seeing a doctor

診る （みる） to examine (medically), to have a look at, to check (a patient's pulse)