A pregnant mum credits her Apple Watch with saving her life after a red alert led to doctors finding blood clots in her lungs.
Rebecca McManus, 24, found herself struggling to breathe after walking up two flights of stairs, but put it down to her asthma and being 22 weeks pregnant.
While sitting down on her sofa, a warning flashed up on her device saying her resting heart rate had jumped to 154 beats per minute (bpm).
According to the NHS, a normal resting heart rate should be anywhere between 60bpm and 100bpm.
Rebecca, from Clydebank, Scotland, rushed to hospital where she was eventually diagnosed with two pulmonary embolisms - a life-threatening condition where blood vessels in the lungs are blocked by blood clots.
The mum-to-be is now on blood thinners, and told the Daily Record: "I was feeling tired and out of breath but I expected that with my second pregnancy.
"I'd walked up two flights of stairs to my flat and I was struggling to breathe.
"I sat down on the couch and my watch alerted me that my heart rate was at 140bpm for over 10 minutes, as if I had been exercising.
"I didn't believe it until I stood up and felt dizzy. Then it went up to 154bpm.
"If it wasn't for my Apple Watch, I wouldn't have realised the danger I was in. It saved my life."
Rebecca went to A&E at the Queen Elizabeth University Hospital in Glasgow on April 30, where she had her blood taken, a chest X-ray and an electrocardiogram (ECG).
But she was initially sent home after doctors put her symptoms down to her baby pushing up into her diaphragm.
Three days later, after her dizzy spells and high heart rate had failed to subside, she went to visit her GP.
After watching her heart rate soar from 80bpm to 140bpm just by standing up from a chair, she was immediately referred back to hospital.
Further tests showed the mum had two life-threatening clots in her lungs.
Pregnant women experience a heightened risk of blood clots which, if left untreated, can lead to strokes, heart attacks and death.
Rebecca is concerned that her symptoms were dismissed three days before the clots were found, and now plans to submit a complaint to NHS Greater Glasgow and Clyde.
She continued: "It is ridiculous that I was sent home after being told I was 'just pregnant'.
"I could have died in a few months thinking my symptoms were just my pregnancy.
"One blood clot can be fatal and I was walking around with two."
A spokesperson for the NHS board said: "While we cannot discuss the details of any case due to the need for patient confidentiality, we would like to apologise to Ms McManus for the distress she has experienced.
"If she does submit a formal complaint, it will be fully investigated by the relevant teams.
"However, if in the meantime she would like to discuss any aspect of her care, we would encourage her to contact us."
