The former Made In Chelsea star was on holiday in Antigua when her health took a turn for the worse.
After returning to the UK, she was admitted to hospital for more than two weeks.
On Instagram, Louise recalled the moment she knew medical help was needed.
“While I was out, I randomly fell asleep in the car, in the middle of the day, and at the beach. I couldn’t walk or pick up Leo,” the 33-year-old explained.
Louise added that she was regularly 'disoriented' but tried to carry on with their planned holiday for 'yonks' so they could create happy memories with partner Ryan Libbey and their two-year-old son Leo.
'The fear increased when I went to the bathroom every 20 minutes, losing a cup full of blood.
'My body was 'surviving', 'masking' and 'compensating', but probably only because I'm young and have a good watch. It was truly a miracle.
“Most people would be in A&E the first day with my symptoms, I have no qualms saying that because I know what my symptoms were and they weren't okay, I'll spare you some of the darker details, but I got a little 'too used to it' with my chronic condition,' she wrote in her caption.
She eventually informed her family that her health was improving without help: 'Things were looking a little dangerous. I couldn't risk getting worse in a foreign country, with a lack of adequate healthcare and without my notes.'
Louise booked an early flight home to the UK and went straight to A&E, where she was admitted.
“I'm a STRONG COOKIE and I'm working hard for a speedy recovery,” Louise told her 1.4 million followers.
The brave star concluded: 'I still maintain that 2024 will be the best ever!'
Do you have a story?
If you've got a celebrity story, video or pictures get in touch with the Metro.co.uk entertainment team by emailing us firstname.lastname@example.org, calling 020 3615 2145 or visiting us Send stuff – we love hearing from you.
MORE: Made In Chelsea star only managed to watch one episode because she was 'horrified'
MORE: Louise Thompson defends partner after fans worried about his 'toxic' food comment