Hypothyroidism (low thyroid secretion) can cause: fear of cold and sweating, anorexia, constipation and bloating, dry skin and nails, weight gain, enlarged thyroid gland, swollen face, dull expression, depression, etc. Excessive secretion of hormones by the thyroid gland (hyperthyroidism) may cause: fear of heat and sweating, irritability, nervousness, weakness, increased appetite, diarrhea, weight loss, enlarged thyroid gland, protruding eyes, shivering, etc. Inflammation or tumor of the thyroid gland may cause: pain, enlargement, mass or abnormal position of the thyroid gland.