One of the commonest reasons for unhappiness is a mismatch between expectations and reality.
This is equally true for a doctor-patient interaction. The patient expects that:
1. the doctor is an expert on everything to do with medicine
2. the doctor will do whatever is needed to make him better
3. the doctor has all the time and money and power to do so
Unfortunately, in today's day and age, its very rare for doctors to be able to satisfy all three conditions . Doctors operate under multiple constraints - personal; intellectual; and financial.
Even if they wanted to do everything for their patient, they are often constrained by reality, and cannot do so, no matter what their personal desires may be.
Ironically, it is patients ( through their lawmakers) who set the constraints as to what doctors are allowed to do and what they are not. However, when this constraint affects their personal care, patients are not likely to be charitable, and dump their anger and bitterness on their personal physician, who becomes a soft target for all the patient's resentment.
The only way to prevent this problem is to ensure that patients have a realistic and intelligent understanding of what the doctor is allowed to do - and what he is not. It's far better for doctors to be transparent, so patients know what the doctor's limitations are. Equally importantly, patients need to do their own homework, so they have a better understanding of reality, rather than leave everything upto their doctor - who is not omniscient or omnipotent !