T3 activates transcription of genes that regulate cellular energy production. Hypothyroidism: slow metabolism, weight gain, cold intolerance, tiredness. Hyperthyroidism: the opposite.
View the study (review) →Thyrotoxicosis causes a picture indistinguishable from severe anxiety: tachycardia, sweating, tremor, insomnia, irritability. A thyroid blood test is mandatory in de novo anxiety.
View the study (study) →Hypothyroidism produces fatigue, apathy, cognitive impairment, weight gain, and depression resistant to antidepressants. Correction with levothyroxine resolves the picture.
View the study (study) →Hashimoto's thyroiditis (anti-TPO antibodies) is the most common cause of hypothyroidism in iodine-sufficient countries. Selenium, vitamin D, and an anti-inflammatory diet may modulate antibodies.
View the study (systematic review) →Information, not medical advice. Scientific evidence reflects the quality of the studies.