Low thyroid generally refers to hypothyroidism. Hypothyroidism is an endocrine disease caused by thyroid hormone resistance or insufficient thyroid hormone, which can lead to lower body metabolism, followed by symptoms such as fatigue, chills, weight gain, loss of concentration and memory, constipation, depression, drowsiness, lack of sweating, loss of appetite, and slow movements. Patients with hypothyroidism may have elevated thyrotropin with decreased thyroid hormone. Patients diagnosed with hypothyroidism usually need to follow the doctor’s instructions to use levothyroxine sodium tablets to maintain the thyroid hormone within a reasonable range, the above symptoms can be relieved. Patients diagnosed with hypothyroidism should actively cooperate with their doctors to avoid delaying their condition.