World Thyroid Day: What's the science behind mood swings?

World Thyroid Day: What's the science behind mood swings?

How does lack of sleep harm a person's endocrine system? What's the link between one's thyroid, emotions and stress? 

CGTN's Health Talk invites Dr. Zhao Weigang, chief physician of the Department of Endocrinology at Peking Union Medical College Hospital, to explain the importance of hormonal balance and how the thyroid quietly controls one's heart rate, mood and even body shape.