A Perth teenager has died while training for a Muay Thai fight, prompting questions about the safety of the sport.

Jessica Lindsay, 18, was cutting weight ahead of an amateur martial arts event when she collapsed from severe dehydration while running on November 10.

She was rushed to hospital but died four days later.

Ms Lindsay, who had less than two years’ experience in the ring, had been cutting weight for a bout where the weigh-in was 64 kilograms.

She collapsed on the day before the scheduled fight.

Jessica Lindsay collapsed while cutting weight for a Muay Thai bout. (9NEWS)

9NEWS understands the teenager was healthy in the lead up to the event.

Ms Lindsay posted to Instagram that she was feeling “fit and healthy” nine days before the fight, but two days before she collapsed she wrote “yeah nah cutting weight is sick hey”.

One doctor told 9NEWS Ms Lindsay may have suffered heat exhaustion.

“There is a point of no return, it is quite extreme and it goes beyond dehydration,” GP Dr Joe Kosterich said.

“It is what some would call heat exhaustion or heat shock.”

Earlier this year, Scottish fighter Jordan Coe died from suspected heatstroke while trying to reach a certain weight for a professional event.

Jessica is believed to have suffered from severe dehydration. (9NEWS)

A fundraising page set up for Ms Lindsay’s family says her case is similar.

The Combat Sports Commission says weight-cutting is not covered in its legislation but that it is constantly reviewing processes and guidelines around contestant health and safety.

Dr Kosterich said the risks posed to amateur combat athletes while they cut weight are serious.

“People may choose to ignore the warning signs because they're focused on what they're trying to achieve and it's an issue for amateurs - professionals will be coached, they will be monitored,” he said.