What are the possible causes for a 46 year old man to get sharp chest pains while climbing stairs?

Pain on exertion: Think heart first and foremost. If the doctor rules out heart disease, then lungs and chest wall muscles/bones/joints should be considered as sources of pain on exertion. Same applies to a 46yo woman, but breasts should be considered also. The question is very important and difficult to answer briefly. Therefore, i will share it with doctors in cardiology, pulmonology, etc.

Many causes: Needs a good check up looking for heart, lung problems or blood disorders like anemia etc.