Polycystic Ovary Syndrome (PCOS)

1. Understanding PCOS before you explain it

Before diagnosing or explaining PCOS to a patient, it is important to understand what is driving the condition. When the physiology is clear, explanations become simpler, more confident, and more reassuring, both in real consultations and in the SCA.

PCOS is best thought of as a hormonal pattern, rather than a single disease, sitting at the intersection of metabolism, hormones, and ovulation.

2. What is PCOS?

PCOS (polycystic ovary syndrome) is a common, multifactorial endocrine condition characterised by:

• Ovulatory dysfunction (irregular or absent ovulation)

• Hyperandrogenism (clinical and/or biochemical)

• Often, but not always, insulin resistance

It exists on a spectrum, meaning patients may present with different combinations of symptoms.

3. Insulin Resistance

A helpful way to view PCOS is by understanding insulin resistance, which is common in PCOS, including in some people who are not overweight.

• Insulin helps move sugar from the blood into the body’s cells

• In PCOS, the body may be less sensitive to insulin

• To compensate, the pancreas produces more insulin

Insulin is also a hormone. Higher insulin levels can affect the ovaries and influence other hormones.

4. How insulin affects ovarian hormones

• Insulin works alongside luteinising hormone (LH) in the ovaries

• Together, they stimulate the theca cells to produce androgens, such as testosterone

• This leads to raised androgen levels

Raised testosterone can:

• Disrupt normal follicle development

• Interfere with ovulation

• Cause symptoms such as acne, excess facial or body hair, scalp hair thinning, and irregular periods

5. Why periods become irregular

• Androgen excess and altered LH/FSH signalling impair follicle maturation

• Follicles become “arrested” rather than releasing an egg

• This leads to oligo-ovulation or anovulation

• Clinically, this presents as irregular, infrequent, or absent periods

Despite the name, PCOS does not mean dangerous cysts. The ovaries often contain small immature follicles that have not developed properly because hormone signals are not lining up.

6. Investigations in PCOS – what we test and why

Investigations are used to support the diagnosis and exclude other causes, not to confirm PCOS with a single test.

Blood tests

Blood tests assess biochemical hyperandrogenism and hormone balance.

• Testosterone

  • Free testosterone is often the most clinically relevant

  • May be raised, or normal with an increased free fraction
    

• Sex Hormone Binding Globulin (SHBG)

  • Often low in PCOS

  • High insulin levels suppress SHBG production in the liver

  • Low SHBG means more testosterone is free and biologically active

Together, raised free testosterone and low SHBG support a diagnosis of PCOS in the right clinical context.

Pelvic ultrasound

• Can be helpful but is not mandatory

• May show multiple small immature follicles and increased ovarian volume

• Ultrasound alone does not diagnose PCOS

• Some patients with PCOS have normal scans

• In younger patients, ultrasound is often avoided

7. How to explain PCOS to a patient

“PCOS stands for polycystic ovary syndrome. It’s a common condition that affects how hormones work in the body.”

“In PCOS, the body can be less sensitive to insulin, which is the hormone that helps control blood sugar. This can affect other hormones, including testosterone.”

“When testosterone is higher than usual, it can interfere with ovulation and cause symptoms like irregular periods, acne, hair changes, and sometimes difficulty getting pregnant.”

“Despite the name, PCOS doesn’t mean you have cysts on your ovaries.”

“It isn’t something you’ve caused, and it’s manageable.”

8. How to explain blood results to a patient

“Your blood tests show that the active form of testosterone is a bit higher than usual, which can explain your symptoms.”

(“A protein that normally keeps testosterone inactive is lower, meaning more testosterone is free and active.”) If you want to give more information about SHBG

“These results aren’t dangerous, but they help us understand what’s driving your symptoms so we can choose the right treatment together.”

Management of PCOS

Principles of management

• Management is individualised

• Treatment depends on what matters most to the patient:

  • Period regulation

  • Skin or hair symptoms

  • Fertility

  • Long-term metabolic health

• PCOS is a long-term condition, so focus on symptom control and risk reduction

1. Lifestyle management (first-line for most patients)

Lifestyle measures are recommended for all patients with PCOS, regardless of weight.

Why lifestyle matters

• Improves insulin sensitivity

• Can reduce androgen levels

• May restore ovulation and improve cycle regularity

• Reduces long-term risk of type 2 diabetes and cardiovascular disease
  

Key points to discuss

• Regular physical activity (aerobic + resistance)

• Balanced diet with reduced ultra-processed foods

• Focus on sustainable changes rather than rapid weight loss

• Even modest changes can improve symptoms

• Avoid blaming language, lifestyle changes support hormone balance and metabolic health.
  

2. Managing irregular periods / endometrial protection

If contraception is acceptable

• Combined oral contraceptive pill (COCP)

  • Regulates cycles

  • Reduces androgen effects

  • Provides endometrial protection
    

If COCP not suitable or not wanted

• Intermittent progestogen (e.g. every 3 months)

  • Protects the endometrium

  • Does not treat androgenic symptoms

3. Managing hyperandrogenic symptoms

• COCP is first-line if appropriate

• Topical acne treatments may be used alongside

• Hair-related symptoms improve gradually

• Set expectations - improvement takes months, not weeks, and some clinical features may not change at all

4. Role of metformin

Metformin may be considered in selected patients:

• Those with features of insulin resistance

• Those at increased risk of type 2 diabetes

• Those who cannot tolerate or do not wish to use hormonal treatments

Metformin is not first-line for all patients.

5. Fertility considerations

• Many patients with PCOS conceive naturally

• Improving insulin sensitivity can improve ovulation

• If pregnancy is desired and conception does not occur, referral for ovulation induction may be appropriate

• Reassure patients that PCOS ≠ infertility

6. Long-term health risks and follow-up

PCOS is associated with an increased risk of:

• Type 2 diabetes

• Gestational diabetes

• Cardiovascular risk factors

• Endometrial hyperplasia (if prolonged amenorrhoea)

Regular follow-up should include:

• Metabolic monitoring

• Review of symptoms and priorities

• Long-term risk reduction

How to explain management to a patient

“Treatment for PCOS isn’t one-size-fits-all. We focus on what matters most to you.”

“Lifestyle changes help improve insulin sensitivity, and medications can help regulate periods or hormone levels if needed.”

“The aim is long-term control and prevention, not just short-term symptom relief.”