Greater fatigue was linked to unusual levels of two thyroid hormones in women with functional somatic syndromes (FSS), a term used to describe symptoms that are difficult to explain and which includes fibromyalgia among its conditions. Specifically, women with FSS had higher levels of the thyroid hormone thyroxine (fT4) and lower levels of thyroid-stimulating hormone (TSH). Low TSH levels were also associated with adverse and traumatic events in early life. The study, “Thyroid functioning and fatigue in women with functional somatic syndromes – role of early life adversity” were published in the journal Frontiers in Physiology. FSS is the term given to a set of distinct physical symptoms that are not attributed to any specific disease, including chronic pain and fatigue, irritable bowel syndrome, and fibromyalgia. Fatigue, either physical or mental, is commonly associated with several diseases, but about one-third of the patients experiencing it find it difficult to explain to their doctors. Fatigue is also one of the most frequent symptoms of thyroid diseases. Researchers were not surprised by this association, since the hypothalamic-pituitary-thyroid (HPT) axis — a set of glands that produce hormones and other substances — is involved in regulating energy levels. Alterations in the HPT axis have been observed in healthy women who report troubling events in early life, like childhood traumas. Early life adversity is also prevalent in women with FSS and, for that reason, researchers decided to investigate if the function of HPT axis is related to fatigue and early life in a group of patients.