Are period blood clots normal – and why do they happen?

While some people often experience small blood clots throughout their period, for others the first time one appears can prompt a bit of panic…fair enough.  

But they’re actually pretty common, usually they can just be wiped away, flushed…and forgotten about.  

We’ve got the flowdown on what causes them, what’s normal, and when to see a doctor. 

What are period blood clots? 

They’re basically little blobs of coagulated blood and tissue which has been expelled from your uterus during menstruation. Healthline describes them as ‘gel-like’ and resembling ‘stewed strawberries or the clumps of fruit you find in jam’, varying in colour from bright to dark red.  

What causes period clots? 

When your uterine lining sheds, it mixes with blood, tissue and mucus which pools at the bottom of the uterus before it’s expelled through the cervix and out the vagina. To help this thickened blood and tissue pass more easily, your body releases anticoagulants, but if your blood flow is faster than your body’s ability to produce anti-coagulants, menstrual clots are released. [1] The heavier your periods, the more likely you are to pass clots.  

What size blood clots are normal? 

So long as you’re only passing clots occasionally, usually at the beginning of your period, and they’re smaller than about 2cm in diameter, then they’re likely nothing to worry about, however, if you regularly pass large clots, it could be a sign of a medical condition which might need treatment, so visit your doctor to get checked out.  

What medical conditions cause period clots?  

While heavy menstrual bleeding is the usual cause of normal period clots, there are a number of other conditions which may make them more likely, or more frequent. These include:  

Fibroids 

Fibroids are muscular tumours (typically not cancerous) which grow in the uterine wall, causing heavy or irregular bleeding, pain during sex, lower back pain, fertility problems and a swollen abdomen. They’re increasingly common as you age.  

Endometriosis 

Characterised by cells similar to the uterine lining – endometrial cells – growing outside the uterus, endometriosis often causes painful periods, pain during sex, fertility issues, pelvic pain, abnormal bleeding and sometimes nausea, vomiting and diarrhoea during your period.  

Adenomyosis 

In adenomyosis the uterine lining grows into the uterine wall, causing it to thicken and enlarge. This often leads to longer periods and heavy bleeding.  

Cancer 

Cancer of the reproductive organs is a rare cause of heavy menstrual bleeding.  

Hormonal imbalance 

A common symptom of a hormonal imbalance is irregular periods, whether they’re more frequent, less frequent, shorter or longer than usual, and off-balance levels of either oestrogen or progesterone can cause heavy bleeding. Common conditions behind a hormonal imbalance can include perimenopause, menopause, significant weight loss or weight gain, high stress levels or other menstrual conditions.  

Miscarriage 

Early pregnancy loss – often before you even know you’re pregnant – can cause heavy bleeding, cramps and clotting.  

When to seek medical help  

If you’re passing clots which are larger than 2cm in diameter, and you’re passing them frequently, then seek medical advice, just as you should if your menstrual bleeding is particularly heavy or painful.  

Similarly, if there’s any chance you could be pregnant and you’re passing clots then seek immediate medical attention, as it could indicate a miscarriage.  

Medical disclaimer:  

This blog is intended for informative and entertainment purposes only and does not constitute medical advice. Please always see your doctor for any queries about your health.  

Source: https://www.healthline.com/health/womens-health/menstrual-clots 

[1] https://www.healthline.com/health/womens-health/menstrual-clots