Single mum Rebecca Ortiz collapsed suddenly at the gym. Days later, she was dead.

A fit and healthy 40-year-old mother, who collapsed at the gym, has died from a brain haemorrhage.

Rebecca Luisa Ortiz, from the UK, fell to the floor in front of her personal trainer and died in hospital just 10 days later, Manchester Evening News reports.

The Manchester beauty therapist leaves behind a 14-year-old daughter, Alexia.

Good friend, Claire Clark, has set up a crowdfunding page as a support for Ortiz’s family.

Clark says the tragic death of her friend on January 15 was “completely unexpected”.

“Rebecca was a caring, considerate woman who took it upon herself to inspire and comfort others, always putting them first,” Clark wrote on JustGiving.

“…She was a healthy woman who took care of herself, her body was her temple, and therefore this has taken us all by huge shock – Rebecca did not have funds aside like most for such an unpredicted financial burden.”

Clark praised the Salford Royal Hospital for their efforts to save the single mother after her ruptured brain aneurysm.

Many paid tribute to the beauty therapist on Facebook.

Beauty therapist colleague, Laura Ashley, said: “This news is devastating to us all, Rebecca was a kind and caring woman who has always been there for each of us – with her words of wisdom and inspiring outlook on life she will be a great loss to us all.”

“Heaven has gained another beautiful angel. You touched so many hearts. You were a beautiful woman inside and out. We will all miss you so much,” friend Terri Williams added.

Clark said Ortiz had opted to be an organ donor and had successfully given “hope and life to another family in need”.

“We take great comfort in knowing this,” she said.

Mamamia has reached out to Clark for comment.

To donate visit here.