It’s completely normal to experience slight changes in your period month to month. Blood flow can also increase when you first start your period, after pregnancy, or during menopause.
However, in many cases, there are other underlying causes for heavy periods. That’s why it’s important to discuss your symptoms with your GP, who can help identify the reason for your heavy bleeding and discuss treatment options.
Which conditions cause heavy periods?
Conditions affecting your womb, ovaries, or hormones can be a leading cause of ongoing heavy periods. Diagnosis can often be difficult, but these conditions are commonly considered when identifying the cause of heavy periods:
Polycystic ovary syndrome:
Polycystic ovary syndrome (PCOS) is a hormonal condition which is categorised by 3 main features — irregular periods, high levels of male hormones, and enlarged ovaries that may contain fluid-filled sacs. Occasionally, women with PCOS experience heavier bleeding during their periods as well as irregularities in the menstrual cycle.
Endometriosis is a condition in which tissue similar to the tissue that normally lines the inside of your uterus — the endometrium — grows outside your uterus. Endometriosis most commonly involves your ovaries, fallopian tubes, and the tissue lining your pelvis, and it can sometimes be a cause of irregular or heavy periods.
Fibroids are abnormal growths that form in the muscle of the uterus and occur in up to 80% of women. Large fibroids can push on internal organs and cause pelvic pressure as well as stimulate the growth of blood vessels, which contributes to heavier or irregular periods and spotting between periods.
These conditions usually require a blood test, ultrasound scan, or small surgical procedure to be diagnosed.
In more serious cases, abnormal bleeding may be caused by tumours, growths, or cancer. If heavy periods are unusual for you, this can be discussed with your GP.
Can stress cause heavy periods?
Stress can also affect your periods. Changes to your psychological wellbeing — such as increased stress, anxiety, or depression — may result in heavier vaginal bleeding temporarily. Your physical and mental health are very much interconnected.
Does heavy bleeding cause blood clots?
Passing blood clots during your menstrual cycle is not uncommon. Most women will experience clots, particularly during heavy flow days at the start of their period. However, regular clotting and large clots (those bigger than a 10 pence coin) may be a cause for concern and should get checked out.