High levels of thyroid hormone were associated with several components of sleep dysfunction, including prolonged sleep latency, difficulty maintaining sleep, and excessive daytime sleepiness. Low thyroid hormone levels/subclinical hypothyroidism lead to longer sleep latency, shorter sleep duration, and lower satisfaction with their sleep quality compared with euthyroid individuals. Limitations: Small sample sizes in previous studies were referenced. The gene discussed is TG; the disease is Sleep disturbance.