What would cause t3 (liothyronine) levels to be abnormal, but tsh/t4 are normal? i'm not pregnant.

Stress and T3 (liothyronine): With stress and "adrenal burnout", essentially a low cortisol state, can cause a rapid conversion of T4 to T3 (liothyronine) (the activated form of thyroid hormones). Diagnoses NEED TO BE MADE WITH A HISTORY AND PHYSICAL EXAM, not by a laboratory value. When I was in Med School, we were taught repeatedly, treat the patient, not the labs. The laboratory values are static values and we are dynamic beings.

Several things: Hi. If your TSH and free T4 are normal, you're normal as far as the thyroid goes. If the doc ordered a total T3 (liothyronine), (liothyronine) that can be off due to abnormal levels of serum proteins that bind T4 and T3 (liothyronine). Also, if you're recovering from (or in a phase of) a subacute thyroiditis, T3 (liothyronine) changes faster than T4 so could be off (unlikely, but possible). Cheers!