The thyroid gland regulates your metabolism which affects your hair follicles. With an underactive thyroid (hypothyroidism), your hair may be coarse, dry and brittle. This can cause hair loss from excessive breakage to hair shedding all over your scalp. If you have an overactive thyroid (hyperthyroidism), you may have slower hair growth, soft/fine hair texture and excessive hair shedding all over your scalp. Once your thyroid is under control by your doctor, your hair loss should improve.
A few weeks to three months after childbirth, the majority of your hair follicles enter into their normal resting stage (telogen stage) which causes widespread hair shedding and can last up to six months. Throughout the nine months, your hair follicles remained in an actively growing stage (anagen stage), therefore, the natural shedding did not occur making your hair thicker and look longer. It was not the prenatal vitamins, which are basic multivitamins…MYTH!