Have you had your thyroid checked? My thyroid was always in the normal range but I found out it wasn't normal for me. It took a good Dr. to figure out I needed to take Synthroid to see if that helped my cold feet, cold hands, thinning hair, dry skin, always tired, weight gain, and general feeling not so great but not sick. My nails started to grow and be strong. It won't hurt to find out if your thyroid is in the low normal range. Ask your Dr. Most Drs. are now aware that 9 out of 10 women have thyroid issues.