Enlargement of the pituitary gland and hypopituitarism are the "broad" types of pituitary gland disorders into which more specific disorders fall. Those specific disorders include, but are not limited to, a deficiency of the following: growth hormone, thyroid-stimulating hormone, corticotropin or prolactin. A deficiency of gonadotropins, which are follicle-stimulating hormones and luteinizing hormones, is also considered to be among the various pituitary gland disorders.
The pituitary gland can malfunction in a number of ways as the result of the development of a benign tumor called an adenoma, the presence of a disease such as tuberculosis or sarcidosis and bleeding into the gland itself. Any of these conditions can easily lead to enlargement of the gland or to hypopituitarism, which is the medical term for an underactive pituitary gland. Hypopituitarism results in a deficiency of one or more pituitary hormones, which in turn results in a number of health problems that present with a variety of signs and symptoms. Pan-hypopituitarism, which is the underproduction of several hormones at the same time, is actually more common than hypopituitarism.
It can, therefore, be said that that the different types of pituitary gland disorders, broadly speaking, are enlargement and hypopituitarism. Growth hormone deficiency causes insufficient growth in all parts of the body where growth takes place, leading to dwarfism if it occurs during childhood. Thinning bones, reduced muscle tissue and excess fat are seen in adult victims. A deficiency of gonadotropins can cause the cessation of menstrual periods and infertility in premenopausal women. It can lead to a decreased production of sperm in males and to Kallmann's syndrome in males and females; Kallmann's syndrome is a condition that can cause color-blindness, a decreased sense of smell and a cleft lip or palate.
Prolactin deficiency interferes with a woman's ability to produce breast milk after childbirth. This is one of the pituitary gland disorders that has no known effects in males. Thyroid-stimulating hormone deficiency causes an under-active thyroid, but it still is considered one of the known pituitary gland disorders when dealing with a case brought on by low levels of pituitary hormones. Corticotropin deficiency can be fatal because it results in an underactive adrenal gland, which is called Addison's disease; low blood pressure; fatigue; and low blood sugar levels.