https://chriskresser.com/low-t3-syndrome-iv-an-autoimmune-disease-youve-never-heard-of/ interesting theory @BadBadBear @bertiedog @Iritu1021 Extract: What is autoimmune hypopituitarism? LAH is characterized by progressive destruction of pituitary tissue, which over time produces a decline in the function of the pituitary gland. (1) When the pituitary is damaged more than one hormone is affected, especially as the disease becomes more advanced. It was originally believed that LAH occurred exclusively in pregnant women. (2) But although prevalence is still much higher in that population, we now know it also occurs in non-pregnant women, men and children. (3) Adrenocorticotropin (ACTH) deficiency is most common (60%), followed by thyrotropin (TSH) deficiency (47%), gonadotropin (FSH/LSH) deficiency (42%), growth hormone deficiency (42%) and prolactin deficiency (34%). What is remarkable about this condition is how unknown it is in spite of its prevalence. It’s true prevalence is unknown, but most investigators believe it is under-reported because it is often misdiagnosed. I’ve seen some estimates that it may affect up to 0.5% of the population and up to 40% of Hashimoto’s patients. How is autoimmune hypopituitarism diagnosed? The reason it’s so often misdiagnosed is that it’s difficult to pin down. It is strongly associated with other autoimmune diseases, which further complicates the clinical picture. In fact, concurrent autoimmune conditions are reported in 20-50% of LAH cases. (4) Interestingly, Yoon et al. injected hamsters with Rubella virus glycoproteins and consistently induced LAH, as evidenced by autoantibodies to pituitary cells and infiltration of the pituitary gland by lymphocytes. (5) This finding suggests there may be some connection between viral infections and LAH. Other investigators have identified antibodies to growth hormone (GH), thyrotropin (TSH), and luteinizing hormone (LH) in cases of LAH. (6) Unfortunately, the only conclusive test for LAH is a tissue biopsy, which is obviously problematic due to the location of the pituitary gland. Low levels of the pituitary hormones can indicate LAH, but they can also be a sign of other functional problems with feedback in the hypothalamus or a primary problem with the hypothalamus itself.