A 'perfectly healthy' 33-year-old woman says it's a 'miracle' she's still alive after she suffered harrowing mid-flight medical emergency, and has issued a warning to other travellers. 

Emily, who goes by the username 'alwayssingingmom' on TikTok, flew 13 hours non-stop from Toronto, Canada, to Dubai last month.

But two-and-half-hours before landing she collapsed after getting up to go to the toilet, the first time she had stood up in over 10 hours.

'I was waiting for the bathroom and I got this really deep dull aching pain in my chest out of nowhere,' she recalled. 

'I coughed three times and that was the last thing I remember.'

In a clip, which has been viewed nearly half-a-million times, she detailed how the fall had left her with a black eye and bruises to her left arm, and she was unconscious for at least five minutes.  

Tests, conducted after they landed, revealed she had suffered a catastrophic blood clot that was cutting off the blood supply to both her lungs.

Called a massive bilateral saddle pulmonary embolism, this is a life threatening emergency that kills about one in four patients who suffer it immediately with more dying for every hour that passes without medical treatment.

Such embolisms can form as a result deep vein thrombosis (DVT) on flights if people sit too long without moving and blood pools in the legs. 

While a DVT clot can remain in the legs, and cause issues like swelling, pain and discoloration, it can also break off and travel to the lungs where it can block critical blood vessels. 

Speaking after returning to Canada, Emily said medics have told her despite being a 'perfectly healthy 33-year-old young woman,' her near death experience was triggered by a combination of not moving enough during the flight and taking oestrogen-based birth control.

Recalling the aftermath of her collapse, Emily said she was extremely lucky that the bathroom had been occupied at the time, otherwise she could been in the airplane toilet alone with no one aware of her medical emergency.

She paid tribute to a doctor that happened to also be on the flight and 'amazing' flight attendants who rushed to her aid. 

'(They) essentially saved my life, they gave me an oxygen tank, carried me to business class, laid me down,' she said. 

'I was vomiting profusely, sweating.' 

She explained how she had to wait a total of six-and-a-half-hours, from collapsing, to the plane landing and then arriving at hospital where her life-threatening blood clot was diagnosed.

'It's essentially a miracle that I'm still alive,' she said. 

After landing, she spent the next six days in a Dubai hospital, but was sharing her story now to help others avoid a similar emergency. 

'Please get up and move on your flights,' she said. 

She added: 'If you are on oestrogen birth control or if you are doing hormone therapy for perimenopause, menopause please just talk to your doctor.' 

Emily detailed in another clip how she has been told she will need to take blood thinning medications for next six months, as well as follow-up scans, to ensure any remaining clots are broken up.

The NHS recommends people travelling on flights longer than four hours move every half hour to reduce the risk of DVT as well as wearing compression stockings. 

Some studies show that for healthy people, the risk of DVT is quadrupled with air travel, with longer flights carrying a greatest risk.

For flights lasting less than four hours, the risk of a DVT is low, with only one estimated case for about every 105,000 flights. 

For flights lasting over four hours, the risk of a DVT dramatically increases to one event per 4,500 flights. For flights lasting 16 hours or more, the risk is one event per 1,300 flights.

 Blood clots are also a rare, but known risk of taking oestrogen, a female sex hormone, medication like some contraceptives and hormone replacement therapy.

The NHS estimates that clots form in about one in every 1,000 women taking a contraceptive like the pill, though not all will suffer a medical emergency. 

However, medics advise that the small risk posed by oestrogen can be increased when combined with factors like not moving on a long flight. 

Experts also highlight the risk of blood clots forming for most women taking oestrogen is incredibly small and that pregnancy carries much of the same risk.