Nearly half of junior NHS doctors have revealed they are suffering from burnout, which experts warn could put patient safety at risk.
The largest study into the condition among young medics found 43% had experienced symptoms, such as emotional exhaustion and lethargy.
It comes amid a staffing crisis in the NHS.
Lead researcher Professor Tom Bourne said: "We found the results of this survey very worrying. The levels of burnout were high, particularly amongst younger doctors. This has serious implications for patients, as we know burnout reduces patient satisfaction, safety and standards of care.
"These results point to an environment in UK hospitals that makes staff unwell and less able to carry out their jobs safely.
"There is a clear need to address both the workplace and culture. Improving our understanding of doctor burnout must become a priority.
"Reducing burnout will improve doctors’ wellbeing with resultant improvements in staff retention, productivity and patient safety."
Consultant gynaecologist Prof Bourne led the study at Imperial College, London.
His team quizzed 3,000 doctors working in his field.
They deal with pregnant women, births and ovarian and cervical cancers. Vice president of the Royal College of Obstetricians and Gynaecologists, Dr Alison Wright, said: “The potential impact of workforce burnout is crucial to our national health service and to patient care.
"This important study provides compelling evidence that there is an urgent need to improve the workplace environment for doctors. We know burnout is associated with worse outcomes for patients, as well as a lack of empathy and rapport."
When all doctors were included in the study figures 36% said they were suffering from burnout. Previous research suggests it is twice as common among doctors than other professions.
The condition is triggered by long-term stress and overload at work.
It is associated with lack of empathy and connection with others.
Burnout reduces productivity and saps energy, leaving sufferers feeling increasingly helpless, hopeless, cynical, and resentful.
NHS doctors and nurses have complained about struggling to cope after years of Tory cuts that have left the service near breaking point.
Many have quit, unable to deal with the physical and emotional stress.
The study was published in the journal BMJ Open.
