An autoimmune disease caused by the body attacking itself, those with the condition are unable to produce insulin.
Simply to live, they have to check their insulin levels with finger pricks and inject insulin several times a day.
It’s a particularly tough diagnosis for children to come to terms with.
Immediately signalling they are different from their peers, it also impacts on every aspect of their lives.
From what they can eat to activities they can take part in, their daily routine has to be carefully managed.
Of course, it also has an impact on the child’s parents and siblings.
And it is for that myriad of reasons that three Falkirk mums have set up a support group to help.
Harris Catlin (10) was just four years old when he was first diagnosed and his parents Julie and Scott immediately felt isolated.
Babysitters fell by the wayside, along with play dates, as people were frightened by the condition.
While the paediatric team at Forth Valley Royal Hospital were on hand for clinical advice, there were no local support groups.
So Julie (40), an ophthalmology staff nurse, launched one online.
She said: “I started a closed Facebook page for parents in January 2018 and there are now 93 members.”
Leanne Browne and her husband Colm moved back to Falkirk last June.
Their son Cameron (8) was diagnosed in June 2017 and they had been members of a similar group in Ayrshire so they quickly signed up.
Earlier this year, Julie and Leanne, along with fellow mum Jillian Muir, founded a monthly support group where children and parents could meet up.
With the emphasis firmly on having fun, Forth Valley T1D Families aims to help normalise life for children living with Type one diabetes and their families.
Julie is the chairwoman, Leanne secretary and Jillian treasurer.
In March, the group was officially affiliated with Diabetes Scotland but it is self-managed and funded by its members.
Every month since, T1D Families has held a free event for Forth Valley families.
Julie used her 40th birthday money to take members trampolining at Jump for Joy in Alloa, in June there was a teddy bear’s picnic in King’s Park, Stirling, and last month Julie took teenagers segwaying at Falkirk Wheel.
“It was a teen-only event,” she said, “as it’s a really difficult time for any child, particularly so for a child with diabetes.”
A family fun day is being held on Sunday, August 11, from 2pm to 4pm at Brightons Cricket Club and new members are invited.
Julie said: “We’d like to thank the club for allowing us to use the facilities free of charge and for providing volunteers.
“It will be a great day for our existing members but we’d also like to invite other families of children with Type one diabetes.
“We know there are so many more people we need to reach – we want to let them know we’re here.
“It’s the club that no-one wants to be in but at least there’s other people in the same situation.
“Our activities also try to focus on the positive, rather than the negative.
“Type one diabetes is 24/7 every day, forever, and it’s a difficult balancing act.
“Everything your child eats has to be weighed and carb counted; their insulin levels have to be checked several times a day and can be affected if they are poorly, active or even by the weather.
“Because children are growing and their hormones changing, it’s a battle to keep them as stable as you can.
“It can be isolating and lonely at times but we’re there to support each other when things are tough.
“The emphasis at our monthly activity events, though, is on the children having fun.
“Harris goes to Kinnaird Primary in Larbert and, although it’s a big school, there are no other children who have Type one diabetes.
“So it’s the first time he has known other kids with diabetes; it has shown him he’s not alone.”
Indeed, at the first group meeting, Harris took such an active role in welcoming members he was nominated for an achievement award from Diabetes Scotland.
He has become firm friends with Cameron, a pupil at St Joseph’s Primary in Bonnybridge where there is only one other pupil with the condition.
Leanne (38) said: “The group is a lifeline for mums and dads but it also helps the children have a sense of normality as they see other children doing finger pricks and having injections.
“I know how much it has already benefited Cameron so we just want as many families to know about the group as possible.
“We’re completely self-funded; we all raise funds so that our activities are free of charge to make sure that no-one is excluded.”
Mums have also enjoyed a night out on the tiles with dads planning to do likewise.
It’s much-needed time off for the parents, as Julie explained: “The hardest thing is getting a good night’s sleep as you’re up checking their levels during the night.
“For Harris, not having the freedom that other people take for granted is the most difficult thing; for me it’s the lack of sleep.”
For Leanne, who works as a quality control manager for a medical device company, fielding probing questions from Cameron has been difficult to handle.
She added: “He keeps on asking when there is going to be a cure.
“It’s hard to explain to your child that, at this moment in time, he’s going to have to do this forever.
“Folk mean well but our kids also face stigma all the time with people assuming they must have eaten too many sweets.”
In the future, Forth Valley T1D Families hopes to fund starter packs for families of children who are newly-diagnosed, with the full backing of the paediatric team at Forth Valley Royal.
But its main goal right now is to reach every affected family in Forth Valley.
New families are invited to attend the family fun day at Brightons Cricket Club on August 11 from 2pm to 4pm.