Save 20% on the key thyroid lab tests. The Top 10 Thyroid Lab Tests to Ask For, and What They Mean. Two primary conditions require a thyroid testing: hypothyroidism and hyperthyroidism. Hypothyroidism occurs when your thyroid isn’t producing enough T3 and T4. Hyperthyroidism is the term for when your body produces too much thyroid hormone. Symptoms and signs of hypothyroidism Fatigue or Weakness Intolerance to cold Muscle aches and cramps Constipation Weight gain or difficulty losing weight Poor appetite Goiter (enlarged thyroid gland) Dry, rough skin Coarse hair or hair loss Eye and face swelling Irregular or heavy menstrual periods Depression Memory loss Slowed thinking and mental activity Increased blood cholesterol levels Symptoms and signs of hyperthyroidism Nervousness, tremor, agitation Irritability Poor concentration Reduced menstrual blood flow in women Racing heartbeat or palpitations Heat intolerance Changes in bowel habits, such as more frequent bowel movements Enlargement of the thyroid gland Skin thinning Brittle hair Increase in appetite, feeling hungry Sweating. If this sounds familiar you may have an undiagnosed thyroid disorder. How do you find out? You can order your lab tests directly there to evaluate your thyroid health. . This promotion can not be combined with other promotions.