How's her resting heart rate today? If it's high (90 and above), she's hyperthyroid. A high resting heart rate at 120 was my first indication that I was going into thyroid storm due to Grave's disease. I was also losing hair and losing weight, and was extremely anxious and irritated, but I hadn't put together all these pieces. The high heart rate sent me to the ER. Bloodwork confirmed the rest.

Agree with the others - get her to the doctor asap. Do not be surprised if there’s an eating disorder, but that’s not the only option. If she’s bulimic, also get a dental check - stomach acid destroys the teeth.

This is not something you should be crowdsourcing. Get your child to a doctor, you idiot.

Definitely should get this checked out. My kid had massive hair loss with Grave’s Disease. I’d go to her ped with a list of all the blood work you want checked.

It’s probably telogen effluvium. Next most likely probably anemia. Unless it itches-does it itch?

Eating disorder.

Or did she have a severe illness or huge life stressor 3-6 months ago? After these types of events, there is a several month delay, then tons of hair drops out

Dermatologist

Get some panel tests. This happened to me around the same time. My testosterone and estrogen were out of whack. I lost about 1/3 of my volume of hair. Still had a ton left and it normalized in about a year. Certainly scary though

Just want to put out there this is a big sign of bulimia and bulimics do not look super "skinny"

Have her seen by a / her doctor.

Thyroid

All of the above and adding has she lost a lot of weight lately? I have and am losing hair like crazy.

Stress
Edocrine system out of whack
Medication causing it
Radiation exposure
Illness/contagion/parasite/fungus

Oh wow that is upsetting, especially for a teen! Maybe iron deficiency? That can definitely cause hair loss. I would go to doctor to run blood tests.
Best wishes to her - the loss is probably not noticeable to others.

DD 14 has tons of long thick curly hair. She is recently shedding like insane amounts. In the shower she is losing clumps/handfuls and when it’s dry she can pull out from the bottom of her pony tail. This has never happened to her before and she is really concerned. Anyone else experience this with a daughter similar age? Thanks.