What causes a really high pitched voice?

I don't have a medical answer for you Abby, I just want you to know that you should be confident of who you are and the way you sound shouldn't be a factor. I grew up talking as if my nose was being pinched all the time (nasaly) up until I was 21, then out of nowhere it just went away. I never questioned it I knew I sounded funny but it didn't matter to those around me because they liked me regardless. So Chin up.