A mom has recalled a difficult conversation she had with a doctor after her teenage daughter fell unwell with ‘popcorn lung’.

Christie Martin received a panicked call from her daughter Brianne Cullen who claimed she was struggling to breathe.

Horrified, Christie rushed the 17-year-old to a nearby ER where she was given oxygen, X-rays and medication before being diagnosed with bronchiolitis obliterans — a health condition better known as ‘popcorn lung’.

It’s an uncommon type of lung disease caused by a build-up of scar tissue in the lungs, which blocks the flow of air.

Little did Christie know that Brianne had started secretly vaping at the age of 14.Recounting the day her daughter started to feel sick, Christie, from Henderson, Nevada, US, said: “[Brianne] went to cheer sick, she had a cough and a sore throat. She was lifting up these kids, tumbling, it’s all very straining.