“Both are disorders of the thyroid gland, but each are completely different in the affect on the organ causing opposite problems.

Confused about the difference between hyperthyroidism and hypothyroidism? You’re not alone. The similar-sounding terms can easily be mistaken for one another, but they have very different—actually opposite—meanings:

Hyperthyroidism (“hyper,” meaning “more”) is when there is too much thyroid hormone in the body.

Hypothyroidism (“hypo,” meaning “less”) is when there is not enough thyroid hormone in the body.”

endocrineweb (https://www.endocrineweb.com/conditions/thyroid/hyperthyroidism-vs-hypothyroidism)