Calcium imbalance
The impairment in the functions of the parathyroid glands is known as parathyroid disorder. Thus, parathyroid glands are endocrine glands located in the neck and they are responsible for the secretion of calcitonin and parathyroid hormones which plays a major role in the regulation of calcium in the blood and skeletal muscles. However, parathyroid disorder usually leads to abnormal levels of calcium in the blood that cause fatigue, epigastric pain, weakness etc.