absolutely both over and underactive thyroid can cause hair loss. if you thyroid is underactive and it's just a mild case sometimes you can get some help by eating kelp supplement. usually you will need a doctor to give you supplemental thyroid hormone. they will use blood work to see what's appropriate. if your thyroid is overactive that makes things harder but it's still manageable.
women hair loss- can a thyroid condition cause hair loss? and if so what can a person do to fix the thyroid problem?