Three patients per week wake up while under anesthetic during surgery, The Daily Mail reported new studies as saying on Tuesday.  

Roughly one patient in every 19,000 spontaneously experience "accidental awareness" after not being given enough general anesthetic. But surgeons are often left completely unaware their patients are awake, because they aren't able to move or make a sound.

"Accidental awareness" is one of the most feared complications of general anesthesia for both patients and doctors. It occurs when general anesthesia is intended, but the patient remains conscious.

According to a three-year investigation by the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland, at least 150 and perhaps several thousand patients a year are conscious while on the operating table. The report said that some suffer long-term psychological damage, according to The Guardian.

Patients have been given muscle-relaxing drugs that temporarily paralyzes them so they cannot tell theatre staff that they are awake in the vast majority of cases. It happens most often during caesarean sections under general anesthetic and during heart surgery. Most experiences are short-lived and happen at the beginning or end of the operation.

Sensations patients experience when accidentally aware included tugging, stitching, pain, paralysis and choking, the study found.

Feelings of dissociation, panic, fear, suffocation and even dying, were also experienced, according to The Daily Mail.

For Maria Paisley, 65, the experience was "truly horrible" when she was undergoing a laparoscopy at Birmingham general hospital over 30 years ago.

"I woke up (it was obviously after the surgery) to the sensation that I was being beaten up and punched around the lower body area," she told The Guardian from Bologna, where she lives. "I was also aware of a tube being pulled from out of my throat. I can't say it has caused any psychological damage but is something I'll never forget. It was truly horrible and really not nice. I wondered whether it was a nightmare or for real."