Ugh. Teachers who double as doctors. Out of control how? She spits out her food and rips out her hair and violently attacks other kids and vandalizes and tantrums and screams angry profanity at the teacher? Or she's pushing boundaries and not listening and having an attitude? Don't let the teacher scare you into the doctor's office.
If you know that your daughter has had a happy loving environment from birth with healthy food and lots of sleep, clear boundaries and good discipline, and her consequences have always been firm and consistent for wrong actions, and she is still totally out of control despite her home environment, only you can know this and consider an evaluation.
If there is any way her home life can be made more positive as well as more firm and consistent with calmly administered consequences based on her choices to do wrong things, then you can probably improve this.
My daughter started pushing some boundaries half way through kindergarten. The teacher said it was normal for kids even if they usually have excellent behavior, they start to feel comfortable with their surroundings and influenced by others and push limits. We let her know I had eyes in the class and EXACTLY what would happen if she was caught being disrespectful, and the warning sufficed since she's never had a reason to doubt it, we've always followed through firmly, and she has no disorders.
If you feel your daughter is testing limits, you probably know best. If you feel her consequences have been super firm and undeniably so dire to her that she would strive at all costs to avoid them, and absolutely consistent, then she may have a disorder. If you suspect she hasn't cared much about the consequences (spirited kids aren't phased by toy removals and time outs, not sure what you use) then you could firm up and compound things. Give and immediate firm consequence as well as removing stuff and letting her earn it back AND doing some chores etc. EVERY time.
Good luck, so many factors are at play, go with your gut. Hopefully your daughter is healthy and the doctor doesn't need to be called in.