A pituitary tumor is an abnormal growth in the pituitary gland. The pituitary is a small gland in the brain. It is located at the base of the brain, behind the back of the nose. It makes hormones that affect many other glands and many functions in your body. Most pituitary tumors are benign (not cancer). They don't spread to other parts of your body. But they can cause the pituitary to make too few or too many hormones, causing problems in the body.

Pituitary tumors that make too many hormones will often cause other glands to make more hormones. That will cause symptoms linked to each of the specific hormones. Many pituitary tumors will also press against the nearby optic nerves. This can cause vision problems. Other pituitary tumors may cause double vision by pressing on the nerves to the muscles that move the eyes. Others may bleed, leading to severe headache. This is known as apoplexy.

Most pituitary tumors don't cause symptoms. So they are not diagnosed. Or they are found only during routine brain imaging or blood tests. About 1 in 4 people may have small pituitary tumors without knowing it.

Below are the main types of benign pituitary tumors.

These tumors are the most common type. They don't make extra hormones. You may not have any symptoms until the tumor grows to a certain size. When the tumor is big enough, it may cause headaches and vision problems. Large pituitary tumors can put pressure on normal pituitary cells. This leads to symptoms caused by decreased hormone production.

These benign tumors are also common. They make too much prolactin. If you're biologically female, high prolactin levels can make your menstrual period irregular, or even stop your period. These tumors can also cause you to make breast milk, even if you are not pregnant or nursing. If you're biologically male, you may have erectile dysfunction or a lack of interest in sex. You may also have enlarged breasts, a low sperm count, decreased bone density or less body hair. In time, you may have headaches and vision problems, such as double vision.

These tumors make too much ACTH (adrenocorticotropic hormone). This hormone stimulates the adrenal gland to make steroids that affect metabolism. These are called glucocorticoids (cortisol). They reduce redness and swelling (inflammation) all over the body. They also slow down your immune system. Too much ACTH can cause Cushing's disease. This disease causes fat buildup in your face, neck, back, belly (abdomen), and chest. Also your arms and legs tend to become thin. You may also have purple stretch marks, bruises, and high blood pressure. These tumors can also weaken your bones. Additionally, it can cause diabetes and hypertension.

These tumors make too much growth hormone. In children, too much growth hormone stimulates the growth of almost all the bones in the body. When that occurs, the result is called gigantism. Gigantism can include increased height (over 7 feet), very quick growth, joint pain, and heavy sweating. In adults, too much growth hormone causes a condition called acromegaly. It may include:

• Extra growth in the skull, hands, and feet.
• Deepened voice.
• A change in the facial appearance because of extra growth in the facial bones.
• A wide spacing of teeth because of the growth of facial bones.
• Joint pain.
• Snoring or sleep apnea.
• Diabetes or impaired glucose tolerance.
• High blood pressure from enlargement of the heart muscle and fluid retention.

• Thyroid-stimulating hormone-producing tumors. These tumors are fairly rare. They make too much thyroid-stimulating hormone. Too much of this hormone leads to increased activity of the thyroid and symptoms of hyperthyroidism. These include weight loss, a fast or irregular heartbeat, and sweating. This is a very rare pituitary condition. Doctors sometimes treat people for an overactive thyroid and only diagnose a thyroid-stimulating tumor after the treatment was unsuccessful, or if the person has headaches or other hormonal problems.
• Gonadotroph adenomas. These tumors are extremely rare. They release excess hormones that stimulate the ovaries or testes.

Experts don't know what causes these tumors. But some syndrome conditions, such as multiple endocrine neoplasia type I (MEN 1) may raise your risk. This condition is passed down through families (inherited).

Symptoms depend on the type of tumor and the area of the pituitary gland that is affected. These tumors can lead to symptoms caused by too much or too little of the pituitary hormones. Each person's symptoms may vary.

The symptoms may also look like other health problems. Always see your doctor for a diagnosis.

Your doctor will ask about your health history and do a physical exam. You may also need one or more of these tests:

• Blood and urine tests. These tests will check hormone levels in your blood and urine.
• CT scan. This test uses X-rays and a computer to make detailed images of your body.
• MRI of the pituitary. This test uses large magnets, radio waves, and a computer to make detailed images of organs and structures in your body without the use of X-rays.
• Visual field exam. If the tumor is pressing on optic nerves, this test may show vision field problems such as loss of peripheral vision.
• Biopsy. During this test, the doctor removes a tissue sample with a needle or during surgery. It is then checked under a microscope. A biopsy can tell if cancer or other abnormal cells are present.

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

Treatment may include:

• Surgery to remove the tumor. Surgery is often a better choice for smaller tumors.
• External radiation (external beam therapy). This treatment sends high levels of radiation right to the tumor cells. Special shields may be used to protect the tissue around the treatment area. These treatments are painless and often last a few minutes.
• Radiosurgery (stereotactic radiosurgery) or gamma knife treatment. This is often one high dose of radiation sent right into the tumor tissue. It causes less damage to nearby tissues. It is not actually surgery. But like surgery, it is a one-session treatment that removes the tumor.
• Medicine. Different types of medicine may be used to control how much growth hormone, prolactin, or other hormone is made by the tumor.

Contact your doctor if your symptoms return or you have new symptoms.

• A pituitary tumor is an abnormal growth in the pituitary gland. Most pituitary tumors are benign (not cancer).
• The pituitary is a small gland located at the base of the brain. It makes hormones that affect many other glands and many functions in your body.
• Symptoms vary depending on the type of tumor and the area of the pituitary gland affected.
• You may need blood and urine tests, a CT scan, MRI, or biopsy to diagnose the tumor.
• Treatment may include surgery, radiation therapy, or medicine.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your doctor tells you.
• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new directions your doctor gives you.
• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are and when they should be reported.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your doctor if you have questions, especially after office hours or on weekends.