The passenger who was violently dragged off his seat on a United Airlines plane, sparking widespread outrage on social media, has spoken out about the incident for the first time.

David Dao, a 69-year-old doctor from Kentucky, confirmed he was the man in the viral videos, which showed him bleeding from his mouth after law enforcement officers tried to remove him from the overbooked flight.

Dr Dao is receiving treatment in a Chicago hospital. Speaking to WLKY, a local cable TV channel, he said “everything” was injured, and that he was not doing well.

His family have issued a statement expressing gratitude for the public's support.

“The family of Dr Dao wants the world to know that they are very appreciative of the outpouring of prayers, concern and support they have received”, the family’s attorney, Stephen Golan, said.

“Currently, they are focused only on Dr. Dao’s medical care and treatment.”

Dr Golan is one of two lawyers hired by the doctor’s family, raising the possibility the father of five could be planning to sue United Airlines.

Man brutally dragged off United Airlines flight: "I want to go home"

The airline released an initial statement to explain that the United Express Flight 3411 in Chicago was fully booked and that staff asked for “volunteers” to take another flight.

It later came to light that passengers were removed so that the airline's own staff could take a seat.

When too few volunteers came forward, law enforcement was tasked to select random passengers and force them off the plane.

During the incident, passengers allegedly heard the doctor say he could not delay his journey because he had appointments with his patients scheduled for the following day.

"He just was not willing to get off the plane. He started yelling at her, 'I'm a doctor. I have patients I have to see in the morning. I have to get back tonight. I can't be delayed,' said Tyler Bridges, a passenger on the flight.

“You can tell he's dazed from being unconscious, confused."

The CEO of United Airlines, Oscar Munoz issued a statement apologising to Dr Dao for his treatment.

“The truly horrific event that occurred on this flight has elicited many responses from all of us: outrage, anger, disappointment,” Munoz said.

“I share all of those sentiments, and above all: my deepest apologies for what happened.”