Emmerdale's Cathy Hope finds her behaviour growing out of control in upcoming scenes on the ITV soap.
Bosses revealed they would be tackling a soap first with the storyline, and the teen has recently confirmed some worrying symptoms.
After experiencing sudden outbursts of anger and very heavy periods, as well as being in pain, she spoke with doctor Manpreet who advised it was related to her periods.
But amid this 'diagnosis' and ahead of a full diagnosis, Cathy's behaviour gets worse in upcoming scenes.
New spoilers reveal she worries her loved ones and becomes reckless, even leaving her life in danger.
Next week, her father Bob Hope is still struggling to help his daughter as he doesn't know what to do or say, and often upsets her.
He's also had a go at her a few times over her behaviour, not fully understanding the cause of her antics.
This has left Cathy feeling isolated and frustrated, not getting the support she needs amid her difficult experience.
Now that Bob is working at the B&B that he owns with Bernice Blackstock, he's at risk of pushing his daughter away further.
Ex Brenda advises him not to let the business get in the way of his responsibilities to Cathy.
However, he's soon doing just that and fails to pick up on some worrying behaviour by the teen.
Later in the week, the kids are off to a gig but Cathy has no intention of being chaperoned by Bob's new partner Wendy.
She soon puts a plan into action and tries to get the other teens to get involved.
But April and the others are soon left concerned by Cathy’s reckless behaviour, as she begins to act out.
Things take a horrifying turn when she ends up leaving her own life in danger - but will she be okay?
Bob realises he has been distracted and that Cathy needs professional help with her possible condition, but can he get through to his daughter?
Emmerdale airs weeknights at 7:30pm on ITV1 and ITVX, with an hour-long episode on Thursdays.
