Gym goers have been warned of the dangers of ‘bigorexia,’ an anxiety disorder which can lead to depression, steroid abuse and – in extreme cases – suicide.

Muscle dysmorphia, described as a form of “reverse anorexia,” is particularly prevalent among men, whose body insecurities can cause them to go to dangerous lengths to make themselves bigger and more muscular. Symptoms can include abuse of supplements, steroids and protein shakes; prioritising working out over family and social life; as well as depression and mania.

The Body Dysmorphic Disorder Foundation believes one in 10 men training in UK gyms have the condition, with instances on the rise and many cases going unreported.

"We're seeing an increased pressure on men to look muscular, create a 'V' shape and have a six pack," Rob Willson, chair of the Body Dysmorphic Disorder Foundation, told the BBC.

"There are thousands upon thousands with it, who are going to be excessively concerned about their appearance, having very poor self-esteem, and also feeling very anxious and very worried. Sometimes individuals can become very depressed and hopeless and that can even lead to suicide."

Little is known about the condition at this stage. The NHS website suggests muscle dysmorphia may be genetic or caused by a chemical imbalance in the brain. There have also been suggestions that life experiences may play a factor, with a possible link to suffering from bullying or child abuse.