The thyroid gland is a butterfly-shaped structure that sits in the front of your neck, just below your Adam's apple. It belongs to your body's endocrine system and plays a vital role in determining your basic rate of energy usage, also known as your metabolism. When your thyroid gland produces abnormal amounts of hormones, you may experience an array of symptoms that includes unwanted weight loss and difficulty losing excess weight.
Understanding Your Thyroid
Your thyroid gland produces a number hormones that circulate throughout your body and signal your cells to burn energy, according to the American Association for Clinical Chemistry's Lab Tests Online. Main examples of these hormones include triiodothyronine, also called T3, and thyroxine, also called T4. Your body regulates the effects of T3 and T4 with a product of your brain's hypothalamus called thyrotopin-releasing hormone. The presence of this hormone causes your pituitary gland to release another hormone called thyroid-stimulating hormone. In turn, the presence of thyroid-stimulating hormone triggers T3 and T4 production in your thyroid gland.
Hyperthyroidism and Weight
Disruptions in your normal thyroid function can create an overproduction of T3 and T4, a condition called hyperthyroidism, according to the National Endocrine and Metabolic Diseases Information Service (NEMDIS). When hyperthyroidism occurs, your body reacts to the increased presence of T3 and T4 by burning energy at a faster rate. This increased energy usage can trigger unwanted weight loss and make it difficult for you to maintain a healthy weight. NEMDIS lists additional potential symptoms that include mood swings, irritability, nervousness, heartbeat irregularities, diarrhea, frequent bowel movements, sleeping difficulties, fatigue, hand tremors and heat intolerance.
Hypothyroidism and Weight
If your thyroid gland produces too little T3 and T4, you may develop a condition called hypothyroidism, NEMDIS reports. The decreased energy usage associated with hypothyroidism can trigger unwanted weight gain and make it difficult for you to lose weight. In addition to these weight control difficulties, NEMDIS reports symptoms of hypothyroidism that include depression, slowed heart rate, facial puffiness, cold intolerance, fatigue, muscle and joint pain, constipation, fertility difficulties and heavy or abnormal menstrual flow.
Causes
NEMDIS lists potential causes of hyperthyroidism that include thyroid gland inflammation, Grave's disease, overuse of thyroid-stimulating medications, overconsumption of iodine and the presence of thyroid growths or nodules. Potential causes of hypothyroidism include thyroid gland inflammation, Hashimoto's disease, use of medications such as lithium or amiodarone, removal of all or part of your thyroid gland and radiation-based thyroid treatments, NEMDIS notes.
Treatments
NEMDIS lists potential treatments for hyperthyroidism, which include medications (propylthiouracil, methimazole), thyroid surgery and use of radioactive iodine-131. The standard treatment for hypothyroidism is a T4 substitute called synthetic thyroxine, NEMDIS explains. The amount of this medication you receive will vary according to factors that include your weight and age, the severity of your thyroid symptoms, your use of other medications and your general health.
