Evidence check: TSH in the context of Schlaf

Thyroid function and TSH levels follow a circadian rhythm: TSH rises at night and peaks in the early morning. Sleep deprivation or poor sleep quality can disrupt this rhythm, leading to slightly elevated TSH levels without true hypothyroidism. However, the effects are moderate and highly individual. A single TSH reading from a self-test without accounting for sleep quality, time of day, and inflammatory markers is clinically ambiguous. The evidence is based on physiological studies, not large randomized trials. For a valid assessment, repeated measurements and medical interpretation are required.