It appears my daughter has an elevated testosterone level. We have an appointment to see the doctor next week.
In the meantime how worried should I be? Because right now I’m pretty damn worried.
High testosterone in women can be due to polycystic ovary syndrome, which is the most common cause (or that is my impression from Googling “elevated testosterone in women”; there are a lot of other causes though, many of them not pleasant) and affects up to 10% of women; it can lead to complications like metabolic syndrome (obesity and diabetes) and heart disease if not treated (among other things, treatment includes birth control pills). You haven’t mentioned any other symptoms (irregular periods, weight gain), so the elevated levels are probably recent.
I was going to say PCOS as well - elevated testosterone is one of the main symptoms, along with irregular periods, weight gain and facial hair. In addition to the issues that **Michael63129 **mentions, it can also cause infertility.
Oh boy.
PCOS can cause infertility, but in many women it doesn’t. I have plenty of friends who have PCOS - I have it too, and the doctor told me I don’t have to worry about infertility. My boyfriend’s sister has it, and she had three healthy kids.
Ok, maybe I won’t panic just yet.
Does she show any symptoms besides an elevated testosterone level? I presume you had it checked for a reason, since I don’t think they do it as part of a regular checkup, but again it could be recent enough so that she hasn’t developed any symptoms (which would be good).
She’s not having regular periods. That’s why they did the blood work, but other than that no symptoms.
You’re catching it early; even if she’s in her late teens, her bod is still changing sexually, so it’s good that you even noticed her periods aren’t ‘regular’; lots of women don’t even HAVE a regular rhythym until after they’ve menstruated several years.
You got it early, whatever it is, so try not to borrow trouble. 
I know, I know, easier suggested than done. But hey, you CAN see a doc about this. 30 years ago, I wouldn’t even have known that was a problem, much less been able to see a doc. It’s not the end of the world.
p.s. My little sis had ALL KINDS Of feminine problems, starting when she was 11. It was pretty much a given that she was so scarred up inside after all that, that kids would be out of the question. Nope; two perfect little hellions.
There is some sort of treatment for some PCOS cases involving insulin which has near miraculous results. Hard to link with my phone, but PCOS + insulin should pull some results.
Your daughter will be OK - it’s good that you’re taking her to the doctor promptly. Come back and report to us next week just how OK she’s gonna be.
Unfortunately the endocrinologist can’t see her till the end of September.
Sorry, I didn’t mean to scare you! Yes, it can cause infertility, but it’s one of the most treatable reasons for infertility.