Thyroid Simple Important Pointers: Thyroid problems are a common cause of symptoms such as weight gain, hair loss, depression, and fatigue. The thyroid gland is a small butterfly-shaped gland in the front of your neck. It makes hormones that control how your body uses energy, makes other important hormones that influence many functions in your body, and regulates the way you use food. In order to know whether you have a thyroid problem or not, you need to see your doctor for an examination and blood tests. Hypothyroidism and Hyperthyroidism Simple Differentiating Points: Hypothyroidism: Low thyroid i.e. underactive thyroid. High TSH and Low thyroid hormones t3, t4 Hyperthyroidism: Overactive thyroid. too much thyroid hormone produced. TSH is low and thyroid hormones t3, t4 higher. Hypothyroidism has symptoms e.g. weight gain, fatigueness, tiredness, slow metabolism, slow bodily functions. Hyperthyroidism has symptoms like weight loss, more energy. In hyperthyroidism, there could be