Whenever I read about people suffering heart, lung, kidney-related diseases which was diagnosed late as a result of test conducted after falling sick, I always feel like why cant it be discover before one falls sick or through regular medical check up.

If one does not want to have have problem/ailment that has to do with heart, lung, kidney or other important organs of the body, must one wait to have any ailment before it will be discovered the lung or kidney is malfunctioning?

My questions are: Can one just enter a specialist hospital and request for a scan/check of important organs of the body to ascertain their wellbeing?
Are there hospitals one can just go to & require for a test to check the state of wellbeing of various organs of the body like lungs, heart, kidney, etc.

Health practitioners in the house, pls advise