The Four Types Of PCOS: How Can You Identify Which One You Have?

What is PCOS?

Polycystic ovary or ovarian syndrome is an endocrine disorder that results in an imbalance of male and female hormones as well as issues with metabolism. PCOS causes your eggs not to develop properly, resulting in the characteristic cysts on your ovaries.

It also has other non-reproductive organ symptoms, such as male-pattern hair growth (hirsutism), and is associated with a higher risk of various conditions, especially type 2 diabetes.

PCOS typically causes fertility problems (in fact, many people with the condition don't know they have it until they become pregnant), although this can be corrected with treatment.

What are the types of PCOS?

There are four distinct types of PCOS. These are referred to as PCOS phenotypes because the type of PCOS you have is associated with changes in body type. The four phenotypes are ranked in severity.

Phenotype A

Phenotype A is sometimes called "full-blown" PCOS. It is characterized by having all three associated issues: hyperandrogenism (excessively high male hormones), ovulatory dysfunction (inability to produce eggs and irregular menstrual cycle), and polycystic ovaries, as seen on imaging.

This is the most common type of PCOS and affects 5 to 20% of reproductive-age women (as well as others assigned female at birth) worldwide.¹

Phenotype B

Phenotype B is also called non-PCO PCOS, as it is not associated with the development of cysts on the ovaries, although ovulatory dysfunction and hyperandrogenism are still present. Despite the name, PCOS is not always associated with cysts, which has led some to think the condition needs renaming.

Phenotype C

Phenotype C is also known as ovulatory PCOS and has both hyperandrogenism and polycystic ovaries, but ovulation occurs, resulting in reduced fertility issues compared to the other type. Most patients with phenotype C have normal menstrual cycles but may have other symptoms of hyperandrogenism, such as facial hirsutism.

Phenotype D

Finally, phenotype D is non-hyperandrogenic PCOS, meaning you have multiple cysts and issues with ovulation but do not have elevated levels of male hormones. This is typically the mildest form.

In general, phenotype A is the most severe form, and phenotype D the least. In fact, patients with phenotype D are metabolically normal and may not need treatment. As of right now, it is unclear whether these are spectrums of the same condition or whether they are actually different issues being lumped together due to a similarity in symptoms.

The fact that the cause of PCOS remains essentially unknown makes it hard to tease out whether these syndromes go together and, indeed, whether any of them have multiple different causes.

The difference between phenotype A and the others is the most significant, with higher weight, higher levels of male hormones, and more issues related to insulin resistance. However, all people with PCOS have some degree of insulin resistance. 

Because of phenotype B, there has been a move to rename PCOS to hyperandrogenic persistent ovulatory dysfunction syndrome (HA-PODS). However, this term would exclude phenotype D. It is very likely that terminology will change in the future as we gain a greater understanding of what PCOS really is and the way it affects your entire body, not just your ovaries.²

How does the type of PCOS you have affect your symptoms?

The basic symptoms of PCOS include menstrual irregularities, difficulty falling pregnant, weight gain, acne, and hirsutism. Hirsutism and acne are associated with high levels of androgens and thus are not found in phenotype D.

As already mentioned, symptoms of phenotype A tend to be the most severe. Those with phenotype A tend to have worse menstrual irregularities, higher weight, and a deranged lipid profile. Phenotype A is also the most common type.

People with phenotype C are less likely to have severe menstrual irregularity and may have normal fertility.

As diagnosis requires multiple symptoms, people with non-A phenotypes may have a delay in their diagnosis and treatment. In some cases, however, those with only mild symptoms may not need treatment unless fertility issues arise. 

PCOS phenotype and diagnosis

Many people with PCOS suffer from delayed diagnosis. The syndrome is often mistaken for other health conditions or missed. Younger people are often mistakenly informed that irregular and painful periods are simply normal for them. The diagnostic criteria for PCOS is also regularly changing as more is understood about the condition. 

In general, the following is needed to investigate the possibility of PCOS:

• Detailed menstrual and medical history: A history of menstrual irregularities, pelvic pain, difficulty falling pregnant, and family history will help assist in the diagnosis and rule out other reproductive organ conditions. 

• Physical examination: A physical examination may be conducted to look for signs of PCOS, such as hirsutism, acne, and obesity.

• Blood tests: Blood tests may be done to measure hormone levels, including testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH), as well as a sugar level to check for any insulin resistance. 

• Ultrasound: An ultrasound scan of the ovaries may be done to look for the presence of multiple small cysts. 

In some cases where the diagnosis is unclear, a laparoscopy may be done to examine the ovaries and fallopian tubes.

Treatment of PCOS and phenotype

For most people with PCOS, treatment focuses on reducing elevated androgen levels. One go-to treatment is oral contraceptives, which make periods regular and bring down androgen levels. Other treatments may be used in people who are attempting to become pregnant.

For the most common type of PCOS, phenotype A treatment may include:

• Lifestyle changes to help control weight

• Oral contraceptives to induce regular periods and reduce hirsutism

• Intermittent courses of progestin tablets to induce periods, which can help if you are trying to fall pregnant

• Clomifene to encourage ovulation if you are trying to get pregnant

• Metformin to lower insulin and blood sugar levels. This may also help with weight loss and increase the chances of pregnancy. 

• Topical creams or laser treatment to remove unwanted facial hair

• Anti-androgen medications. You should not get pregnant when taking these.

• Treatments for acne

Treatment might be adjusted for the other phenotypes, although oral contraceptives are often helpful — as long as you are not trying to get pregnant. For example, phenotype D is not associated with elevated androgens, so medication to bring them down is not useful. There is little difference in treatment between A and B.

Often, the treatment program will be tailored to your age, symptom severity, and whether you want to fall pregnant, rather than the PCOS phenotype you have. If you have phenotype D, then you may not need treatment at all unless you are trying to get pregnant and have irregular cycles.

What is insulin-resistant PCOS?

Almost all patients with PCOS have some degree of insulin resistance (IR), but it is worse for phenotype A. It appears that insulin resistance is a key marker for the condition and can eventually lead to type 2 diabetes. Insulin resistance can be detected by looking for hyperinsulinemia (elevated levels of insulin in the blood). 

Insulin resistance is a condition where the body's cells do not respond properly to insulin, a hormone that regulates glucose (sugar) metabolism. Insulin resistance occurs when the body's cells don't respond normally to insulin, and as a result, the pancreas produces more insulin to try to overcome the resistance.

Not every patient with PCOS has insulin resistance, especially if you are not overweight. However, insulin-resistant PCOS is more common than non-insulin-resistant. Studies show that at least 38–88% of the PCOS population of patients with PCOS are overweight or obese.³

How is the adrenal system involved in PCOS?

PCOS may be, in part, a condition of the adrenal glands. If you have PCOS, it is not uncommon for your adrenal glands, in addition to your ovaries, to produce higher levels of testosterone. About 20 to 30% of people with PCOS have adrenal androgen excess. Additionally, many patients have hypersecretion of other adrenocortical hormones, such as corticosteroids. This is also commonly seen in the siblings of PCOS patients.⁴

Because of this, it's believed that at least some cases of PCOS are caused by an inherited abnormality in the adrenal system. However, not everyone with this abnormality goes on to develop PCOS, suggesting there are environmental factors as well. PCOS associated with higher adrenal androgens is sometimes called adrenal PCOS, although this is not considered a "type" of PCOS in the same sense as types A through D discussed above.

Can PCOS be caused by inflammation?

Chronic low-grade inflammation is associated with PCOS. This inflammation appears to be associated with dietary triggers, especially glucose. Inflammation and oxidative stress appear to directly stimulate the ovary to produce excess androgens.

This does not mean that PCOS is caused by eating too much sugar. But given the fact that so many PCOS patients have insulin resistance and the apparent link, people with PCOS should limit glucose intake. However, the effect appears to be linked to hyperandrogenism; that is to say, excessive glucose consumption might cause somebody who is already prone to hyperandrogenism to develop PCOS.

Any inflammation is made worse if you are overweight. Increased adipose tissue (abdominal fat) tends to increase inflammation in general, and this may partially explain why overweight people are more likely to have PCOS. However, in at least some of these cases, PCOS is causing the weight gain.

When to see your doctor

First of all, it is not normal to have irregular periods once you are through adolescence. Many teenagers do experience significant menstrual irregularity as their system matures. It's also normal to have irregular and lighter periods as you enter perimenopause.

If you are of reproductive age, it is not normal to have irregular periods, and you should talk to your doctor about them. Irregular periods can be a sign of significant health conditions and should be discussed with your doctor. You should also talk to your doctor if you consistently experience painful cramping that interferes with daily life; again, we are often told that this is normal, but it is not and may be a sign of a treatable health condition.

Your doctor can help you investigate the cause of your irregular periods and refer you to a gynecologist if needed.

Talk to your doctor if you develop acne after adolescence. This can be a sign of PCOS as well as pregnancy, stress, and some medications. The treatments that work well for adolescent acne tend not to work as well for adults, so you should talk to your doctor about the best treatment for you.

If you have symptoms of hyperandrogenism, such as excessive facial hair, male pattern baldness, or enlargement of the clitoris, absolutely talk to a doctor.

Many people with PCOS only find out they have it when they try to get pregnant and find themselves referred to a fertility specialist.

The lowdown

PCOS is a complex and poorly understood condition. It is often split into four different types depending on the symptoms and key markers seen.

Some people mistakenly think that PCOS types have to do with causes, such as adrenal issues or inflammation. This is not the case. The four types depend on three main factors, namely the presence of hyperandrogenism, ovulatory dysfunction, and polycystic ovaries on imaging.

We don’t know exactly what causes PCOS, although it seems to combine both genetic and environmental factors.

You should talk to your doctor if you have symptoms of PCOS, but be ready to advocate for yourself, as this condition is often underdiagnosed, especially when not all of the key markers are present.