i might be talking out of my butt hole (it really wouldn't surprise me)...

but there are different reasons why someone can have a thyroid problem. but then... depends on how you define 'thyroid problem' in particular. if T3 and T4 being either too high (hyperthyroidism) or too low (hypothyroidism) IS having a thyroid problem then there are other causes of that than an autoimmune problem.

For instance... Pituitary tumors can result in excess or insufficient TSH which in turn results in the thyroid producing high T3/T4 (hyperthyroidism) or low T3/T4 (hypothyroidism). But pituitary tumors aren't autoimmune. Or hypothalamic tumors can result in excess or insufficient whatever it is that tells the pituitary how much or little TSH to produce which in turn affects the T3/T4 production of the thyroid (resulting in hyper or hypothyroidism). Hypothalamic tumors aren't autoimmune either.

So I guess I thought that an autoimmune disorder (e.g., Graves disease) is one cause of hyperthyroidism (or early detection can be the cause of low TSH and a thyroid that produces T3/T4 independently of TSH levels). But that hyper and hypothyroidism weren't themselves autoimmune disorders because one can't infer from high or low T3/T4 that the cause is autoimmune. Though... The MOST LIKELY cause is autoimmune.