Patient Luke Rovira has joined striking junior doctors on the picket line outside Bristol Royal Infirmary.
Mr Rovira, with medical tape attaching a tube to his body, waved a British Medical Association union flag on the picket line.
He also had “pay doctors” stickers on his torso as he joined the strike on a hot day in south-west England.
Up to 47,600 junior doctors are on strike for 72 hours from 7am on Wednesday to 7am on Saturday in a row with the government over pay.
Health chiefs have demanded the “quickest possible resolution” to the junior doctors' strike to mitigate the impact of industrial action on the National Health Service, but there is no sign of a deal being reached.
Speaking outside University College Hospital, London, trainee anaesthetist Arianna Zembryzcka, 27, criticised proposed pay reforms.
“The government’s 5 per cent pay rise was frankly disrespectful and disgraceful. It will not even cover this year’s inflation let alone years of pay erosion,” Ms Zembryzcka said.
One junior doctor in Leeds, who asked not to be named, said: “I can get by, but it’s harder as the cost of living goes up … I think it’s frustrating more than anything. We are not worth 26 per cent less than our colleagues were in 2008.”
BMA chairman Philip Banfield joined junior doctors on the picket line at Royal Sussex County Hospital in Brighton on the first day of the strike.
“The plan is to achieve industrial action safely and getting the message to government that junior doctors are here for the long haul because they care so much about the NHS and patients,” he said.
The BMA is calling for “full restoration” of junior doctors' pay, which it says has been cut by 26 per cent. The government has offered 5 per cent to end the dispute.
Health Secretary Steve Barclay said it was “extremely disappointing” that the BMA was going ahead with further strike action and warned it could put patient safety at risk.
From Monday, the BMA will be re-balloting junior doctors to extend its mandate on industrial action and said it could go on until March 2024 or beyond. Last week, hospital doctors' union the HCSA also sent ballot papers to junior doctors in a bid to extend their mandate.
Meanwhile, members of the Royal College of Nursing in England are voting on whether to extend their mandate on strikes until the end of this year. The Society of Radiographers' 20,000 members in England will be balloted on industrial action in the coming weeks.
Prof Banfield said: “Junior doctors have choices and our latest survey shows around half of them are thinking about leaving the NHS.”
NHS boss Amanda Pritchard described the strike by junior doctors as a “serious business continuity incident” and “therefore a serous risk to patient safety”.
NHS England director Prof Stephen Powis said working as a junior doctor was the “toughest time of [his] life” and praised the current cohort as a “hugely valued” part of the health service.
He also repeated his hopes that the government would publish a long-promised workforce plan for the NHS.
