The thyroid gland is one of the largest endocrine glands in the body, which is located in the front part of the neck below the larynx (Adam’s apple) in front of the trachea. It has two side lobes connected by the isthmus in the middle. Thyroid gland normally weighs 15 to 20 grams in adults.
Moreover, the thyroid gland contains follicular cells which are responsible for the secretion of two major hormones, thyroxin (T4) and triiodothyronine (T3). The thyroid gland needs iodine from foods to secrete thyroid hormones.
Thyroid hormones (TH) are very important since they affect every cell and every organ in the body. They regulate metabolism in adult, slow down or speed up heartbeat, and also regulate the digestive system. In addition, they control body temperature, appetite, protein composition and muscle contraction.
Hyperthyroidism (overactive thyroid) is a condition in which the thyroid gland produces too much of the thyroid hormone in the body, thus speeds up metabolism and energy consumption and causes hyperactivity. When hyperthyroidism develops, a goiter (enlargement of the thyroid) is usually present.
Causes for Hyperthyroidism
- Graves’ disease: An autoimmune disease. It is the most common cause around the world of the excessive production of thyroid hormones T3 and T4). Graves’ disease is hereditary, therefore, the examination of one family members may reveal other individuals with thyroid problems.
- Benign thyroid tumor (toxic goiter).
- Toxic multinodular goiter. The existence of benign tumors of the thyroid gland.
- Thyroiditis: there are several types of thyroiditis including Hashimoto and DeQuervain’s.
These types of inflammations may at the beginning, increase the secretion of thyroid hormones, hyperthyroxinemia.
Often one can heal from these types after several months;
However, complication of the condition may cause thyroid dysfunction and decrease the secretion of thyroid hormones.
- Thyroid storm: Which is an acute and sudden hyperactivity that occurs usually due to wrong treatment of hyperthyroidism, or an infection, an injury, extreme psychological conditions (stress, fear), and non-treatment of diabetes.
- Amiodarone: an antiarrhythmic medication used to treat and prevent a number of types of irregular heartbeats. It is structurally similar to thyroid hormone and may cause either hyperthyroidism or hypothyroidism.
- Hyperthyroidism after childbirth which occurs in about 7% of women during the year after giving birth. Usually the disease passes through several stages, the first one is hyperthyroidism. This form of hyperthyroidism usually corrects itself within weeks or months without the need for treatment.
- Secondary hyperactivity due to a pituitary disorder or tumor.
- Excessive consumption of iodine whether from food or from medications that contain iodine.
- Also lack of iodine consumption.
- Increased appetite loss and weight loss.
- Nervousness, anxiety, discomfort and also hyperactivity.
- Marked swelling of the thyroid gland and protruding eyes or exophthalmos. (Usually in Graves’ disease)
- Fine, brittle hair.
- Rapid heartbeat (tachycardia).
- Muscle weakness.
- Excessive sweating.
- Puffiness around the eyes.
- Irregular menstrual cycle.
- Trouble sleeping (insomnia).
- Heat intolerance.
- Also Diarrhea.