Many GPs across Britain are working above safe levels, leading doctors have said.
The Royal College of GPs said family doctors have a "relentless" workload.
The comments come after a survey of 900 GPs across the UK found that each deals with 41.5 patients a day, according to GP magazine Pulse.
Dr Mary McCarthy, vice-president of the European Union of General Practitioners (UEMO) and a member of the British Medical Association's general practitioners committee, told Pulse: "Around 25 contacts is safe."
Pulse found that one in five GPs (20%) is dealing with double this number.
Patient contacts include face-to-face and telephone consultations, home visits and e-consultations.
Some GPs told Pulse they have 70 contacts a day.
Commenting on the poll, Professor Helen Stokes-Lampard, chairwoman of the Royal College of GPs, said: "This survey backs up what the college has been saying for years - that many GPs and our teams are regularly working way beyond what could be considered safe for patients, and potentially jeopardising our own health and well-being.
"GPs expect to be busy, and we are making more consultations than ever before as we strive to deliver the best possible care to all our patients who need it, but the workload at the moment is relentless and it's taking its toll.
"It is not necessarily the number of consultations we are making on a daily basis, it's the content of those consultations, and our patients are increasingly presenting with more complex, chronic conditions - many of which require much longer than the standard 10-minute consultation.
"As well as clinical work, we have other urgent duties, such as prescription reviews, hospital letters, ensuring records are up to date - and there is a limit beyond which we worry that we are not practising safely.
"Our workload needs to be addressed - it has risen at least 16% over the last seven years, yet the share of the overall NHS budget general practice receives is less than it was a decade ago, and our workforce has not risen at pace with demand."
Dr Richard Vautrey, chairman of the BMA's general practitioners committee, said: "We know that unmanageable and unsafe workload is the primary reason behind doctors leaving general practice, which is leading to serious issues including practices closing to new patients and other surgeries closing entirely.
"This workload pressure also means GPs are increasingly suffering from burnout and patients are being put at risk of unsafe care.
"The BMA has called for practices to be empowered to set their own capacity limits for safe working, which includes limiting the number of consultations per day.
"Fewer consultations would mean longer contact time with patients, leaving doctors better able to ensure safe, high-quality care, that many feel is not possible within the current 10-minute consultation."