Frequent yawning and lack of energy may be caused by physiological factors, or it may be caused by sleep apnea syndrome and hypothyroidism. 1. Physiological factors: If insomnia occurs at night, the quality of sleep decreases or the sleep time is not enough, it may be manifested in yawning, lack of energy, dizziness and sleepiness the next day. 2. sleep apnea syndrome: due to snoring at night, resulting in lack of oxygen in the body, and even sleep apnea in severe cases, the brain and other organs of the body do not get a good rest after the lack of oxygen, and there may be frequent yawning and lack of energy. 3. Hypothyroidism: Due to insufficient secretion of thyroid hormones, neuromuscular excitability decreases and metabolism and energy metabolism slows down, so frequent yawning and lack of energy may occur. If there is frequent yawning and lack of energy, it is recommended to consult a doctor in time to clarify the causative factors and follow the doctor’s instructions for symptomatic intervention.