How are TSH and sleep related?

The relationship between TSH (thyroid-stimulating hormone) and sleep is complex and influenced by circadian rhythms and the sleep-wake cycle. TSH exhibits a pronounced daily rhythm: highest levels occur during nighttime deep sleep, while lowest levels are measured in the late afternoon. Sleep deprivation or disrupted sleep can alter this rhythm, often leading to elevated TSH levels, suggesting reduced negative feedback from thyroid hormones. Conversely, thyroid dysfunction (e.g., hypothyroidism) can impair sleep quality, causing fatigue or contributing to sleep apnea. The evidence is primarily observational and physiological; robust randomized controlled trials directly testing causality are limited. Therefore, the strength of evidence is moderate. Individual TSH readings should be interpreted alongside sleep quality, stress, and other lifestyle factors. No specific supplements or diets are warranted based solely on this relationship.