Swollen feet and the thyroid gland may be related. Thyroid disorders such as hyperthyroidism or hypothyroidism may cause symptoms of swollen feet. 1. Hypothyroidism: Due to the decrease in thyroid hormone levels, the body increases mucin, resulting in mucous edema, which may start as swelling of the face or eyelids, and with the progression of the disease, symptoms of swollen feet may appear. 2. Hyperthyroidism: patients with hyperthyroidism may have the specific manifestation of anterior tibial mucous edema, which mostly occurs in the lower third of the anterior tibia, and is also seen at the dorsum of the foot and ankle joints, and therefore may manifest as swelling of the feet. 3. Heart failure caused by untreated hyper- or hypothyroidism can also cause secondary swelling of the feet. It is recommended that patients with swollen feet go to regular hospitals in time to improve the relevant examinations and standardize the treatment under the guidance of doctors to avoid delays in the condition.