Abnormal uterine bleeding means any vaginal bleeding that happens outside of your regular menstrual period. It is always considered abnormal and always deserves medical attention. This article explains the common causes, what to expect at different life stages, and how Canadian women can get the right help quickly.
What Is Abnormal Uterine Bleeding?
Abnormal uterine bleeding is vaginal bleeding that occurs between your expected periods. It can range from light spotting to heavier bleeding that soaks through a pad or tampon. No matter how mild it seems, this type of bleeding should never be ignored.
Doctors sometimes use the older term metrorrhagia to describe this condition. However, the term “abnormal uterine bleeding” is now more commonly used in Canadian and international medical guidelines. The key point is simple: if you bleed when you are not expecting your period, something is worth investigating.
According to the World Health Organization’s guidance on menstrual health, abnormal uterine bleeding is one of the most common reasons women seek gynaecological care worldwide. In Canada, it is also one of the top reasons for referrals to a specialist.
Common Causes of Abnormal Uterine Bleeding
The causes of abnormal uterine bleeding vary widely. They depend on your age, hormonal status, and overall health. However, there are several well-known causes that doctors look for first.
Hormonal Imbalances
Hormones control your menstrual cycle. When they are out of balance, bleeding can happen at unexpected times. This is one of the most common reasons for abnormal uterine bleeding, especially in younger women and those approaching menopause.
An irregular hormonal cycle can cause the lining of the uterus to build up and shed at the wrong times. As a result, you may experience spotting, light bleeding, or even heavier-than-usual bleeding between periods. Your family doctor can check your hormone levels with a simple blood test.
Uterine Polyps and Fibroids
Polyps are small, non-cancerous growths on the inner wall of the uterus. Fibroids are benign (non-cancerous) tumours that grow in or around the uterine wall. Both can cause bleeding between periods.
These growths are very common. In fact, many women have fibroids without knowing it. However, when fibroids or polyps cause abnormal uterine bleeding, treatment is usually available and effective. Your doctor may recommend an ultrasound to check for these.
Infections
Infections of the uterus or fallopian tubes can also cause abnormal bleeding. Endometritis is an infection of the uterine lining. Salpingitis is an infection of the fallopian tubes. Both are serious and need prompt medical treatment.
These infections are often related to sexually transmitted infections (STIs). Therefore, if you have abnormal bleeding along with pelvic pain, fever, or unusual discharge, see a doctor right away. Walk-in clinics across Canada can help you get tested and treated quickly.
Pregnancy-Related Causes
Bleeding during what should be a non-menstrual time can sometimes signal a pregnancy-related issue. This includes an early pregnancy, a miscarriage, or an ectopic pregnancy — where the embryo implants outside the uterus.
An ectopic pregnancy is a medical emergency. If you think you could be pregnant and you experience abnormal uterine bleeding, seek care immediately. Your provincial health plan covers emergency visits, and most walk-in clinics can do a pregnancy test on the spot.
Cancer and Precancerous Conditions
In some cases, abnormal uterine bleeding can be a sign of cancer. This includes cancer of the cervix, uterus, or endometrium (the lining of the uterus). It is important to note that cancer is not the most common cause. However, it must always be ruled out.
This is why doctors take abnormal bleeding seriously at every age. Furthermore, catching cancer early greatly improves outcomes. Regular Pap smears and follow-up care through your provincial health programme are your best tools for early detection.
Abnormal Uterine Bleeding by Life Stage
The causes and significance of abnormal uterine bleeding change depending on where you are in life. Understanding this can help you and your doctor find the right answer faster.
Teenagers and Young Women
In the first few years after a young woman starts her period, cycles are often irregular. The body is still learning to regulate hormones. As a result, some bleeding between periods is not unusual during these early years.
However, this does not mean it should be ignored. A family doctor or paediatrician can assess whether the bleeding is part of normal development or a sign of something else. In some cases, low-dose oral contraceptives are prescribed to regulate the cycle and reduce abnormal bleeding. This is a well-established and safe treatment option.
Women of Reproductive Age
For women who are in their reproductive years — typically ages 20 to 45 — abnormal uterine bleeding should always be taken seriously. There are many possible causes at this stage of life, including polyps, fibroids, infections, and hormonal shifts.
In addition, women who have recently started a new hormonal contraceptive (such as the pill, patch, or IUD) may notice some spotting or breakthrough bleeding. This often settles down after a few months. However, if the bleeding is heavy or does not stop, speak with your doctor. A higher-dose formulation or a different contraceptive method may be recommended.
Pregnancy must also always be considered in this age group. Your doctor will likely order a pregnancy test as one of the first steps when investigating abnormal bleeding. For more information on what to expect during a gynaecological assessment, visit Mayo Clinic’s overview of vaginal bleeding between periods.
Women Around and After Menopause
Menopause marks the end of menstrual periods. A woman is considered to have reached menopause after 12 consecutive months without a period. Any vaginal bleeding after this point is considered abnormal and must be investigated promptly.
Post-menopausal bleeding can signal several conditions, including cancer of the cervix or uterine lining. Doctors in Canada typically investigate this with procedures such as a hysteroscopy (a camera inserted into the uterus), an endometrial biopsy, or a Pap smear. Treatment depends on what is found, but early action leads to far better outcomes.
Even if you have clear signs of menopause — such as hot flashes, night sweats, and the absence of periods for more than six months — any new vaginal bleeding still needs medical evaluation. Do not assume it is harmless without checking with your doctor.
How Is Abnormal Uterine Bleeding Diagnosed?
Diagnosing abnormal uterine bleeding involves several steps. Your doctor will start with a full medical history and a physical exam. They will want to know when the bleeding occurs, how heavy it is, and how long it lasts.
Common diagnostic tools include:
Blood tests — to check hormone levels, thyroid function, and rule out anaemia or clotting disorders
Pregnancy test — often one of the first steps for women of reproductive age
Pelvic ultrasound — to look for fibroids, polyps, or other structural issues
Pap smear — to screen for cervical cancer or abnormal cells
Hysteroscopy — a camera procedure to look inside the uterus
Endometrial biopsy — a small sample of the uterine lining sent for laboratory testing
Your family doctor may handle some of these tests directly. In other cases, they will refer you to a gynaecologist. Most provincial health plans in Canada cover these diagnostic procedures when medically necessary.
Treatment Options for Abnormal Uterine Bleeding
Treatment depends entirely on the cause. Therefore, getting an accurate diagnosis first is essential. There is no single treatment that works for everyone.
Hormonal Treatments
Hormonal therapies are among the most common treatments for abnormal uterine bleeding caused by hormonal imbalances. These include oral contraceptive pills, hormonal IUDs, progesterone therapy, and other hormone-regulating medications.
These treatments help regulate the menstrual cycle and reduce abnormal bleeding. They are often very effective. Your doctor will choose the best option based on your age, health history, and whether you are trying to conceive.
Surgical Treatments
When polyps, fibroids, or structural problems are the cause, surgery may be needed. Options include hysteroscopy to remove polyps, a procedure called endometrial ablation (which destroys the uterine lining), or in more serious cases, a hysterectomy (removal of the uterus).
Surgical options are generally considered when other treatments have not worked. Your specialist will walk you through the risks and benefits of each option. All surgical treatments for medically confirmed conditions are covered under provincial health plans across Canada.
Treating the Underlying Infection or Condition
If an infection is the cause, antibiotics are the primary treatment. If a thyroid disorder or blood clotting issue is behind the abnormal bleeding, treating that condition often resolves the bleeding as well. This is why a thorough diagnosis matters so much.
When to See a Doctor About Abnormal Uterine Bleeding
Any vaginal bleeding that occurs outside of your regular period is a reason to speak with a healthcare provider. This is true no matter your age. Do not wait to see if it resolves on its own, especially if the bleeding is heavy or accompanied by pain.
You should seek care right away if you experience:
Heavy bleeding that soaks through more than one pad per hour for two or more hours
Abnormal bleeding with severe pelvic or abdominal pain
Bleeding after menopause (more than 12 months without a period)
Bleeding that you think could be related to a pregnancy
Fever, chills, or unusual vaginal discharge along with bleeding
Feeling dizzy, faint, or unusually tired alongside the bleeding
For non-emergency concerns, start with your family doctor. They are your first point of contact in the Canadian healthcare system and can order tests, provide referrals, and offer guidance. If you do not have a family doctor, a walk-in clinic is a great alternative. Most provinces also have telehealth lines staffed by registered nurses available 24 hours a day.
For general guidance on women’s health and when to seek care in Canada, Health Canada’s women’s health resources are a reliable starting point.
As always, this article is for general information only. Please consult your family doctor or a qualified healthcare provider for advice specific to your situation.
Frequently Asked Questions About Abnormal Uterine Bleeding
What is the most common cause of abnormal uterine bleeding?
The most common cause of abnormal uterine bleeding is a hormonal imbalance that disrupts the normal menstrual cycle. Uterine polyps and fibroids are also very frequent causes, particularly in women of reproductive age. A doctor can identify the cause through blood tests, ultrasound, and a pelvic exam.
Is abnormal uterine bleeding a sign of cancer?
Abnormal uterine bleeding is not usually caused by cancer, but cancer must always be ruled out, especially in women after menopause. Cervical and uterine cancers can cause unexpected bleeding, which is why prompt medical evaluation is so important. Early detection through Pap smears and biopsy greatly improves treatment outcomes.
Can birth control cause abnormal uterine bleeding?
Yes, starting a new hormonal contraceptive can sometimes cause spotting or breakthrough bleeding, which is a form of abnormal uterine bleeding. This often settles within two to three months as your body adjusts. However, if the bleeding is heavy or persistent, speak with your doctor about adjusting your contraceptive method or dosage.
When should I go to the emergency room for abnormal uterine bleeding?
You should go to the emergency room if abnormal uterine bleeding is very heavy, if you feel dizzy or faint, or if you have severe abdominal pain. Post-menopausal bleeding and bleeding that may be related to a pregnancy also warrant urgent care. In Canada, emergency departments and provincial telehealth lines are available around the clock.
How is abnormal uterine bleeding treated?
Treatment for abnormal uterine bleeding depends on the underlying cause and may include hormonal medications, antibiotics for infection, or surgical procedures such as polyp removal or endometrial ablation. Your doctor will choose the best approach based on your age, diagnosis, and health goals. Most treatments are covered under provincial health plans in Canada.
Is it normal to have abnormal uterine bleeding after menopause?
No, any vaginal bleeding after menopause is considered abnormal uterine bleeding and should be evaluated by a doctor without delay. It can be caused by conditions ranging from hormonal changes to more serious issues like uterine or cervical cancer. A hysteroscopy, biopsy, or Pap smear can help identify the cause quickly.
Key Takeaways
Abnormal uterine bleeding is any vaginal bleeding that occurs outside of your normal period — it is always worth investigating. Causes vary by age and can include hormonal imbalances, fibroids, polyps
