Doctors are warning about the dangers of the "pass out" challenge. The practice is popular among teenagers who film themselves being strangled and share the footage online.

The challenge - known as the 'American Dream', the 'pass out' game or the choking game - involves teens depriving themselves of oxygen to achieve a high which causes them to lose consciousness and faint.

The fad is gaining popularity among young people on social media sites.

But doctors are now warning of the risks which include seizures, brain damage and even death.

Last year a teenage boy was admitted to Temple Street Hospital in Dublin after taking part in a challenge.

Parents are being advised to talk to their children about the dangers of the practice.