What Are Pituitary Disorders?
The pituitary gland is a small, pea-sized structure that sits at the base of the brain, just behind the bridge of the nose. Despite its tiny size, it has earned the name "the master gland" as it controls the release of hormones that influence nearly every system in the body. This includes everything from growth and development to reproduction, metabolism, stress response and overall quality of life. The brain's hypothalamus sends signals to the pituitary via a small stalk and tells it when to release each hormone.
When this master gland produces either too much or too little of a specific hormone, pituitary disorders occur. Hypopituitarism or pituitary failure is a condition that occurs when production drops across multiple hormones. The symptoms vary wildly depending on which hormone is affected. This is why these disorders can be tricky to spot. Some patients notice fatigue and weight changes and others experience infertility, irregular periods or loss of sex drive. The pituitary sits so close to the optic nerves which can cause a growing tumour to press on vision pathways. This causes headaches and peripheral vision loss that often goes unnoticed until it becomes significant.
Pituitary gland disorders generally fall into two camps which are overproduction or underproduction of hormones. On the overproduction side, a prolactinoma is the most common pituitary tumour. It pumps out excess prolactin, the hormone responsible for milk production. In women, this causes irregular periods, breast tenderness and sometimes unwanted milk production. It often shows up as low testosterone, reduced libido and erectile difficulties in men.
Acromegaly happens when too much growth hormone is produced in adulthood. This causes hands and feet to enlarge and facial features to coarsen. Patients may notice ring or shoe sizes creeping up. It causes gigantism, which is excessive height, if this occurs in childhood before growth plates close. Cushing's disease involves a pituitary tumour that drives the adrenal glands to overproduce cortisol. This leads to rapid weight gain, purple stretch marks, thinning skin and muscle wasting.
Hypopituitarism, on the underproduction side, means the gland fails to produce adequate levels of one or more hormones. This can stem from tumours, surgery, radiation, head trauma, or have no clear cause at all sometimes. Diabetes insipidus is a different kind of pituitary problem. This is when the gland doesn't produce enough vasopressin, an anti-diuretic hormone, and leads to excessive thirst and enormous volumes of dilute urine. This is completely unrelated to the more common diabetes mellitus.
