The endocrine system controls and regulates the complex functions of the human body. Complex bodily functions are controlled by special chemicals called hormones which are secreted by glands. The glands which comprise the endocrine system include the hypothalamus, the pituitary, thyroid, pineal and adrenal glands, the pancreas, the ovaries and the testes. Exposure to radiation damages endocrine gland cells and reduces the glands' ability to function normally.
Secondary Adrenal Insufficiency
According to the National Endocrine and Metabolic Diseases Information Service, secondary adrenal insufficiency is an endocrine disorder that occurs when the pituitary gland fails to produce enough of the hormone called adrenocorticotropic, or ACTH. The pituitary gland is a small pea-shaped gland located below the hypothalamus at the base of the brain. ACTH stimulates the adrenal glands to produce cortisol which functions to maintain blood pressure and cardiovascular function. It also slows immune system responses, maintains blood sugar levels, and regulates the metabolism of proteins, carbohydrates and fats. Secondary adrenal insufficiency can be caused by damage to the pituitary gland resulting from radiation for the treatment of pituitary tumors.
Hypothyroidism
Hypothyroidism occurs when the thyroid gland, a butterfly-shaped gland located in the front of the neck, fails to produce enough of the hormones called triiodothyronine, or T3, and thyroxine, or T4. The thyroid hormones regulate metabolism, and affect brain development, breathing and the functions of both the cardiac and nervous systems. These hormones affect body temperature, muscle strength, menstrual cycles, weight and cholesterol levels. Hypothyroidism is a side effect of radiation therapy administered to treat cancers in the area of the larynx.
Premature Ovarian Failure
MayoClinic.com lists radiation therapy as one cause of premature ovarian failure. This refers to the loss of normal ovarian function before the age of 40. Premature ovarian failure occurs when there are few or no ovarian follicles which are still responsive to the follicle-stimulating hormone, or FSH, and the luteinizing hormone, or LH. Radiation is one of the most common causes of toxin-induced ovarian failure in which the genetic material of the cells is damaged.
Thyroid Cancer
According to MayoClinic.com, exposure to high levels of radiation can lead to the development of thyroid cancer. Radiation exposure can result from treatment for cancers of the head and neck, fallout from nuclear accidents and testing of nuclear weapons.
