Explain one of the core tenants of biomedical ethics

There are 4 key pillars of medical ethics by which all doctors should follow. These are; autonomy of the self, beneficence, non-maleficence and justice. I'll explain one in more detail - autonomy.
Autonomy is the idea that all patients have full control of both their own bodies and the treatments and medical procedures that their bodies can undergo during their time with their doctor. As such it implores doctors to always seek consent from patients and to abide and act upon this consent, even if it goes against suggested medical practices. For example, if a doctor considers a specific treatment to be the best option for a patient but the patient would rather explore alternative methods of treatment and so does not give consent, the doctor must and should always respect that decision. Furthermore, autonomy encompasses the need for discretion and privacy between patient and doctor such that a private and respected doctor-patient confidential relationship is established whereby the doctor does not disclose specific or major details of any patient's condition or treatment.