I'm glad you have gotten the thyroid testing started!! yes, the thyroid can be a factor in your nails. I've noticed many changes in my nails - and in my hair - during the course of my illnesses and each one means something different. Here is what was a very interesting pdf that I believe is full of information:
www.medicine.virginia.edu/clinical/departments/medicine/grad-ed/geri/learning-materials/learning-modules/NailExamination.pdf And as someone that gained 40 lbs in less than 3 months without changing one thing in my life (other than stress levels), I'm so glad you are being insistent on this!! It's been 2 years since that time, and I am only just now losing that weight - and only by taking the thyroid meds and ignoring diet advice from my doc!!! I had to listen to what my body needed/wanted instead. I've lost about
20 lbs this month alone.