Period Problems - Understanding How Hormones Play a Role

By Alyssa Quimby, MD

Are you someone who struggles with heavy or long periods?  Do you frequently leak through your period products or been told you’re anemic as a result of your periods?  If this is you, you don’t have to live like this.  You deserve better.  And the first step is educating yourself on possible causes. 

We think of abnormal bleeding in 2 categories – structural causes which I reviewed last month and hormonal causes which we’ll discuss today.

Understanding your hormones

The lining of our uterus which is called the endometrium, grows and sheds each month in response to a delicate balance of hormones – mainly LH, FSH, estrogen and progesterone.

LH stands for Luteinizing hormone – it’s the hormone that rises dramatically to signal ovulation each month.

FSH stands for follicle stimulating hormone – not surprisingly, it stimulates the follicles (little cysts in in our ovaries) to grow before the dominant follicle releases an egg each month during ovulation. 

Estrogen – our dominant female hormone – is produced by our ovaries and is responsible for most of our secondary sex characteristics – breast development, pubic hair pattern, etc.  Estrogen is also what causes the lining of our uterus to become thicker.  When estrogen levels begin to drop as we ease toward menopause, this can cause hot flashes, vaginal dryness, mood changes, period irregularities and a number of other symptoms.  Really makes you realize how much of a role estrogen plays in our female bodies!

Progesterone – this is the hormone that helps to support a pregnancy should one occur which is where it gets its name – “Pro Gestation” (gestation meaning pregnancy).  Progesterone rises after ovulation which stabilizes the lining of the uterus, making it even thicker with good blood flow – a perfect place for fertilized egg to land and implant.  Progesterone is secreted by the corpus luteum cyst – which is the follicle that released an egg during ovulation that month. 

Ovulation – why it’s important

Regular periods in someone who is not using birth control is a vital sign – it indicates that you are ovulating and that your hormones are cycling the way they should.  If you stop ovulating – even for just one cycle - this causes your period to change at least temporarily. 

When you don’t ovulate, your ovaries don’t create a corpus luteum cyst which in turn doesn’t secrete the progesterone needed to stabilize the lining of the uterus.  The result is that the lining of the uterus gets thicker and thicker until eventually it sheds as a very heavy and long period. 

Anovulatory causes of abnormal bleeding

Anovulatory is the fancy medical term for not ovulating.  There are MANY reasons one may not ovulate.  One of the most common is due to stress, diet changes, intense exercise, or other life events like travel, etc.  Anovulation for this reason tends to be very temporary.  So if you’ve ever missed a period and then the following month had things mostly back on track, this is probably why.

Other more long-term causes of anovulation include: thyroid disorders, PCOS, and a benign pituitary tumor called a prolactinoma.  When our thyroid hormones are out of whack this also messes with the balance of the hormones responsible for our period.  This is the same reason prolactinomas can cause issues with our period – the hormone prolactin when it’s very elevated, blocks production of other pituitary hormones (which include LH and FSH).  And when these hormones are lower than they should be, the result is changes in your cycle.  Pretty crazy how interconnected our body is right?!

PCOS stands for Poly Cystic Ovarian Syndrome.  It’s a syndrome by which females don’t ovulate regularly and produce higher than average levels of male hormones like testosterone or something called DHEA.  Women with PCOS tend to have issues with acne, excess hair growth, increased belly fat, and have a predisposition to diabetes.  PCOS can impact women of all shapes and sizes and all ethnicities.  And it’s a constellation of symptoms which means you don’t have to have all the symptoms to meet criteria for the diagnosis.  The one thing you absolutely have to have however is irregular periods.  I often have patients coming to my office concerned that they could have this condition, and my first question for them is always – tell me what your period like?  If it’s regular (even if it’s heavy) then it’s not PCOS. 

Other Hormonal Causes of Abnormal bleeding

Another hormonal cause of abnormal bleeding that I commonly see is called endometrial atrophy.  This is the thinning of the lining of the uterus that can happen when estrogen levels are low. 

Estrogen tends to decrease as we are entering menopause, but it also is low during the postpartum period (particularly during breastfeeding).  Even some types of birth control can cause our estrogen to be low. 

A thin uterine lining allows the walls of the uterus to rub together during activity (often worse with exercise or sex).  This causes irritation that can cause light bleeding or spotting that is often random and not associated with a period.  To determine if this is your issue your doctor will likely do an ultrasound to measure the lining of the uterus.

So there you have it – a pretty comprehensive list of hormonal causes of abnormal bleeding.  As you can imagine, this is just the tip of the iceberg on this topic and each of the conditions could warrant their own post (or novel).  I’d recommend if you are struggling with your period (whether it’s heavy or long or irregular) you should absolutely see your doctor so you can get started on the path to figuring out what is going on.  I hope you can use this information to be more informed and to ask more questions.  Our bodies are amazing and complex and knowledge about what is happening can only benefit you.