The pituitary is a pea-sized gland that is located at the base of the brain. In response to signals from the brain and other glands in the body, the pituitary secretes hormones that control growth, sexual development and function, and metabolism. Certain pituitary dysfunctions can cause weight loss.
Facts About the Pituitary
The pituitary is divided in two parts, the anterior lobe and the posterior lobe. The anterior lobe secretes hormones that control the adrenal, the thyroid and the reproductive glands. The posterior lobe secrets two hormones: antidiuretic hormone, which helps with the body's fluid balance, and oxytocin, which triggers the contractions of the uterus during the birthing process.
Conditions That Cause Weight Loss
The main hormone abnormality that can cause weight loss is hyperthyroidism, a condition in which the thyroid gland, sometimes because of overstimulation from the pituitary, secretes excess thyroid hormone. Another hormonal problem that can cause weight loss is adrenal insufficiency, a condition in which the pituitary fails to produce enough ACTH, the hormone that stimulates the adrenal glands to secrete steroid hormones.
Apart from weight loss, hyperthyroidism can cause jitteriness, increased appetite, increased sweating and trouble concentrating. MedlinePlus also lists high blood pressure, protruding eyes, hair loss and weakness as symptoms of excessive thyroid hormone secretion. Adrenal insufficiency causes fatigue, muscle weakness, loss of appetite and weight loss. According to National Endocrine and Metabolic Diseases Information Service, other symptoms of adrenal insufficiency include nausea and vomiting, low blood pressure, a craving for salty foods, low blood sugar and absent periods in women.
The treatment of hyperthyroidism depends on the severity of symptoms. If symptoms are mild, antithyroid medications can be used to try and block the effects of the excess thyroid hormone. If this is unsuccessful, radioactive iodide can be used to destroy the thyroid gland or surgery can be used to remove it. If the cause is a pituitary tumor that is over-stimulating the thyroid, surgery may be indicated. The treatment for adrenal insufficiency is replacement of the hormones that the adrenals are not making.