Seeing the Doctor: When To Rule Out PCOS

conditions similar to PCOS
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Most women have good intuition. They know their bodies and know when something isn't right. Unfortunately, many women see several doctors before getting a proper diagnosis. Doctors may ask a lot of questions or have some diagnostic tests performed before making any conclusions. Polycystic ovary syndrome is one condition that requires excluding other conditions before making a diagnosis

The following are some conditions that are similar but different from PCOS.

Thyroid Disease

The thyroid gland is a small gland located in the front of the throat that regulates much of the body’s metabolism. It produces two hormones, triiodothyronine (known as T3), and thyroxine (known as T4) in response to a third hormone, thyroid stimulating hormone or TSH, which is produced by the pituitary gland in the brain. These hormones (T3 and T4) are released into the circulation either free or bound to a protein known as thyroxine-binding globulin (TBG). Free thyroid hormones are considered to be the active form of the hormone, whereas the bound hormones act as a reservoir and generally are not considered to be active.

Because of the effect on the body’s metabolism and other hormones, many of the symptoms of thyroid disease are similar to PCOS. When too much thyroid hormone is produced - a condition known as hyperthyroidism -- a woman may experience irregular periods, abnormal and temporary hair loss, heat intolerance, weight loss or other symptoms.

If too little thyroid hormone is produced, known as hypothyroidism, symptoms include absent or infrequent periods, weight gain, fatigue and cold intolerance. The doctor will want to measure the amount of thyroid hormones in the blood to determine if an imbalance in those hormones could be behind the symptoms you are experiencing.


Prolactin is a hormone produced by the pituitary gland, a tiny gland located in the brain. Normally found in pregnant or nursing women, it acts on the mammary glands to assist in lactation. When inappropriately produced (as in non-nursing women), it can cause irregular periods and milk production (galactorrhea). While there are some pituitary tumors that can cause increased production of prolactin, there are other things that can also cause hyperprolactinemia. Breast stimulation, intercourse, and certain medications can all be to blame. There is a simple blood test that can be performed to evaluate the level of prolactin in the blood. If it comes back high, your doctor may order an MRI (Magnetic Resonance Imaging) to rule out a pituitary tumor as the cause of the elevated test. Also, PCOS itself can cause mild increases in prolactin.

Congenital Adrenal Hyperplasia

This disorder occurs when the adrenal glands -- small glands located on top of the kidneys -- do not produce enough cortisol and aldosterone but produce too many androgens. Cortisol is the body’s main stress hormone, helping the tissues and organs cope during times of stress. Aldosterone helps to regulate the concentration of sodium and other electrolytes in the body.

Women born with this disease may experience irregular periods, excessive hair growth, and failure to menstruate. While this disease is typically diagnosed in early childhood, doctors must make sure that these hormones are in balance when evaluating someone for PCOS. In addition to genetic tests that can detect this, your doctor may order urine and blood tests to detect levels of aldosterone and cortisol.

Cushing Syndrome

Cushing’s Syndrome is a disease where there is an overproduction of adrenal hormones. This could be caused by a few different things, including a tumor on the adrenal glands which produces too much cortisol, or other hormonal imbalances which may affect secretion of adrenocorticotropic hormone (ACTH).

ACTH stimulates cells of the adrenal glands to produce adrenal hormones. Adrenal hormones are responsible for a variety of functions within the body, including carbohydrate metabolism, electrolyte regulation, and management of stress on the body. Patients with this syndrome may have higher than normal levels of androgens, contributing to many of the same symptoms of PCOS. Additionally, patients may notice weight gain, a round and full face, increased urination, or skin changes. Your doctor may order urine or blood tests to measure the amount of adrenal hormones present.


Jensen, Jani R. and Ruben Alvero. "Polycystic Ovarian Syndrome." Reproductive Endocrinology and Infertility: The Requisites in Obstetrics and Gynecology. Ed. Mark Evans, MD. Philadelphia: Mosby, 2007. 65-75.

Pagana, Kathleen Deska and Timothy J. Pagana. Mosby's Manual of Diagnostic and Laboratory Tests. Second Edition. St. Louis: Mosby, 2002.

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