"Battlefield medicine", "third world conditions" and a system "on its knees" are some of the expressions being used by doctors to describe the situation in England's Accident and Emergency departments.
Dr Richard Fawcett, an emergency medicine consultant at University Hospitals of North Midlands NHS Trust, said he was heartbroken to see so many frail and elderly patients languishing in corridors.
On Twitter, he apologised to patients in the Stoke area for "3rd world conditions of the dept due to #overcrowding".
His colleague Dr Gareth Davies also took to Twitter to say: "Royal stoke on its knees.
"But we definitely saved a very unwell man's life this am.
"Keep going team ED...you are amazing!"
The trust sent out a statement recognising the "sustained pressure" in the system in the region, adding: "Our staff want the very best for our patients and at times they find the situation frustrating, which can be reflected on social media."
Dr Anu Mitra, a consultant in emergency medicine at Imperial College Healthcare NHS Trust, wrote: "Like everyone else we've been practicing corridor medicine on a brutal shift today.
"This is battlefield medicine.
"For next few weeks it won't be exception but norm.
"That we're retaining any semblance of kindness, politeness and teamwork is testament to our remarkable staff.
"But it's TOUGH, and it's SO hard to do things well when ED's >200% of capacity."
Another NHS doctor, Chris Turner, wrote: "It's 0400 and I've been lying awake for the last hour worrying about how we manage the department when my shift starts in 12 hours time.
"The last time the job felt so impossible for me was Mid-Staffs.
"This can feel like a personal failure to staff; it's not, it's a system fail."
The hashtag #NHSCrisis has become one of the top trending UK topics on the social media site.