Thyroid hormone levels may fluctuate due to stress, diet, medications, childbirth, and menopause.
Hypothyroidism can be caused by Hashimoto’s thyroiditis (autoimmune condition), postpartum thyroiditis (temporarily affects 5-9% of women after childbirth), iodine deficiency, or a non-functioning thyroid gland (from birth).
Hyperthyroidism can be caused by Graves’ disease (autoimmune condition), overactive nodules within the thyroid, or excessive iodine.