Flight Attendant Current
Communication Breakdown; Situational Awareness; Confusion
Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Passenger Misconduct
General None Reported / Taken
Company Policy; Environment - Non Weather Related; Human Factors
Aircraft X; Passenger X who was with her husband stated she was unable to wear her mask due to a medical condition and provided a letter. I explained that she was supposed to inform the gate agent.  She stated; 'The gate agent was rushing us through.'  My major concern was she wore her mask as she entered the plane the forward Flight Attendant later informed me and kept it on up until we were in flight. I politely asked her to cover her nose with the mask and that's when she handed me the letter.In any event I know we have a procedure that passengers go through with medical and we should be notified on our departure report; nevertheless; I never want to be put in a situation like this again and my concerns are how to handle a situation like this in the near future.  I was scared to insist she put her mask on because her letter never disclosed her illness and I didn't know whether her illness/es were a matter of life or death if she was to wear her mask. My other concerns are the risk she could have put my passengers and crew in.Customer did not go through proper channels to clear medical.
Flight Attendant reported a passenger did not go through proper channels to clear medical in regards to not having to wear a face mask.