What’s up with my period?? – Structural causes of abnormal bleeding

This will be the first article in a series that explores the wide variety of things that can give us abnormal bleeding.  Not surprisingly, there are LOTS of potential causes.  Some are easier to fix than others.  But pretty much all of them can thankfully be helped.  When we think about “structural” causes what I mean is something about the actual structure of the uterus that is making you bleed – not something systemic like a hormonal imbalance or an underlying medical condition. 

Structure of the Uterus

To better understand the structural causes of bleeding, it’s important to understand the structure of the uterus.  Your glorious uterus is a muscular organ typically about the size of your fist.  It’s made up of 3 layers – the outermost layer is shiny and smooth and prevents other organs from sticking to it – this is called the serosa.  The middle layer is the muscular wall which makes up the majority of the uterus – this is called the myometrium.  The myometrium grows and stretches as the uterus changes to support a pregnancy.  It’s also the layer that contracts when we have period cramps or to help push out a baby.  And the inner layer is lining of the uterus that is hormonally active – it thickens and sheds in response to our normal hormones of the menstrual cycle and it’s called the endometrium.  This is the layer that bleeds normally during our period. 


Structural causes of abnormal bleeding can impact these layers – but mostly impact the endometrium, since this is the layer that bleeds normally anyway.  One such cause is a uterine polyp.  A polyp is a small ball of tissue grows in the lining of the uterus.  We don’t completely understand why polyps form and there doesn’t seem to be any particular genetic predisposition to them.  They vary in size – typically they are about 1 to 2 centimeters but they can be as large as 4 centimeters.  The size of a polyp doesn’t necessarily correlate with the amount of bleeding you have.  Small 1 centimeter polyps can make you bleed like stink whereas some 4 centimeter polyps cause basically no symptoms and are just found incidentally.  Polyps typically cause spotting – spotting around the time of your period, spotting not related to your period at all, spotting after sex, or all of the above.  Polyps can be diagnosed in several ways – with a special ultrasound called a saline ultrasound or hydrosonogram that allows your doctor to look at the lining of the uterus, or with a biopsy of the lining of the uterus that can detect cells found specifically in polyps.  It is possible for polyps to go away on their own, but most of the time they need a minor surgery to treat them called a hysteroscopy – where you doctor uses a small camera and instruments to remove the polyp through your cervix and vagina – no cuts in your skin at all!  Some doctors do this in their office but most of the time it’s done in an outpatient surgery center.


The next structural cause of abnormal bleeding is one that most people have heard of – Fibroids.  Fibroids are muscular growths or tumors that can occur all over the uterus.  The medical term for them is leiomyoma and they are typically benign, meaning not cancerous.  Where they grow and how large they are generally dictates what symptoms they cause.   Fibroids on the outside of the uterus in the serosa layer, which we call subserosal fibroids, usually don’t cause symptoms unless they are very large.   Fibroids in the muscular middle layer can cause symptoms of pelvic pain or pressure, but usually not unless they are quite large – like the size of a grapefruit or larger.  These fibroids are called intramural fibroids.  And lastly, fibroids that form in the lining of the uterus tend to cause the most problems with bleeding, even when they are quite small. They are called submucosal fibroids and are diagnosed and treated in the same way that uterine polyps are. 


The last structural cause of bleeding that we’ll discuss is called adenomyosis.  This is where the glandular tissue that lines the endometrium begins to grow into the muscle wall of the uterus.  This causes the uterus to become enlarged and leads to heavier more painful periods.  Unlike fibroids and polyps which are discrete lesions with defined borders that can be surgically removed, adenomyosis has no definitive borders.  To remove it would mean to remove the uterus completely.  So instead, we typically treat this with medicines like the birth control pill or even hormonal IUD which can be quite effective in treating symptoms. 

If you’ve made it to this point in the article, it’s likely because you are someone you are close to struggles with heavy periods or other abnormal bleeding.  Let me remind you that this is just the tip of the iceberg when it comes to causes.  So if you think any of this information applies to you, the first step is a consultation with your Ob/Gyn.  You don’t have to live with annoying bleeding and you deserve to figure out what’s causing it so your problem can be treated once and for all. 

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