Most doctors and nurses are competent and you are blessed to be under their care. But some are not and their incompetency or ambivalence can kill you. The old joke asks, "know what you call the medical student who finishes LAST in every class in medical school?" Doctor. You can't tell how skilled or knowledgeable someone is by how friendly or professional appearing they are.
Ask any surgical nurse who should do your surgery and they will tell you quickly who to choose and who to run from. They see the surgeons who never develop surgical excellence and those who do. I am not picking on doctors because I have personally witnessed heart stopping (pun intended) gross negligence and/or ignorance by nurses. It is well known that many, many, hospital acquired infections are caused by nurses, doctors and other hospital staff failing to wash their hands.
My husband is a physician and I am an RN and we often wonder at how non medical professionals navigate our health care system. We manage only because we know what the clinical standards are and know how to evaluate care being provided (or not).
If you are in the hospital try to do the following: Be observant, ask questions, request that staff wash their hands and to clean medical devices like stethoscopes that will be used on you and if at all possible, have a friend or family member with you that can advocate and protect you. It is too much to expect that someone who is sick enough to be hospitalized also be vigilant and monitoring the care provided. :(. Unfortunately though your safety may depend on you or so one else doing that.