When traveling with a medical bag containing a Continuous Positive Airway Pressure (CPAP) machine or other essential medical equipment, you can typically carry it as hand luggage. In most cases, there is no need to notify the airline in advance.
However, it's always a good idea to check the specific policies of the airline you are traveling with. Ensure that your medical bag meets the carry-on size and weight restrictions.
If you need to take medical equipment that goes over the airline's luggage limits, you might need to provide a medical document to avoid any extra baggage fees.
For any specific questions or concerns, it’s a good idea to reach out to your airline directly.