The most effective way to lose weight with hypothyroidism is usually to give medications such as levothyroid hormone to treat hypothyroidism, so that the symptoms of hypothyroidism are relieved, thyroid hormone levels return to normal, and there will be a certain degree of weight loss. Weight loss can also be achieved by combining diet and exercise, taking care to rule out other diseases that may cause obesity. When hypothyroidism, thyroid hormone synthesis and secretion is reduced, patients show low metabolic symptoms, such as slow heart rate, fatigue, weakness, mucous edema and other manifestations, which can easily lead to obesity. Obesity at this time is mostly due to mucin deposition in the subcutaneous tissue, resulting in pseudo-obesity, through the levothyroxine hormone replacement therapy, mucous edema is reduced, and weight loss usually occurs. Contraindications to levothyroxine include hypersensitivity to the drug and tachyarrhythmias. Adverse reactions include angina pectoris, arrhythmias, palpitations, tremors, headache, insomnia, diarrhea, vomiting, excessive sweating, and flushing. When thyroid hormone levels return to normal and mucous edema subsides, patients who are still obese should control their diets and appropriately increase a certain amount of exercise, which also helps to lose weight. At the same time, attention should be paid to exclude other diseases that may lead to obesity, such as Cushing’s syndrome, non-alcoholic fatty liver disease. Patients with hypothyroidism and obesity should be under the guidance of the doctor, improve the relevant examination and active treatment.