The thyroid gland is a small butterfly-shaped gland in the neck, just in front of the windpipe (trachea). One of its main functions is to produce hormones that help regulate the body's metabolism (the process that turns food into energy). These hormones are called triiodothyronine (T3) and thyroxine (T4). Many of the body's functions slow down when the thyroid doesn't produce enough of these hormones.
Esophageal spasm is a disorder of the rhythmic waves of muscular contractions (peristalsis) of the esophagus. The cause of this disorder is not known. Symptoms include chest pain and difficulty swallowing.
If these symptoms are due to serious heart conditions, they often will be accompanied by other serious symptoms, including difficulty breathing, bluish coloration of the lips or fingernails, and pain in the shoulder and arm. In some cases, esophagus symptoms may be a sign of a serious or life-threatening condition.