Breakthrough Bleeding: Causes and When It Happens

Breakthrough bleeding, or spotting, is a common experience for people with female reproductive organs. While bleeding outside of your menstrual period can be concerning, it usually is not cause for worry. Birth control use and hormone changes during pregnancy or perimenopause are common causes of breakthrough bleeding, but sometimes, it is a sign of an underlying condition that requires treatment.

This article discusses the causes and characteristics of breakthrough bleeding, how to manage it, and when to discuss heavy or irregular uterine bleeding with a healthcare provider.

First, Let's Define Breakthrough Bleeding

Breakthrough bleeding is unexpected uterine bleeding between your regular menstrual periods. It can occur at various points in your menstrual cycle, during pregnancy, or when using birth control. It is also common during the years leading up to menopause (perimenopause) due to fluctuating hormones.

Some people may experience occasional light spotting, while others may experience heavy bleeding that lasts a day or more. The blood may appear pink, red, or reddish-brown, and some people experience abdominal cramping (similar to period cramps) with the bleeding.

Why Breakthrough Bleeding Happens on Birth Control

Breakthrough bleeding is a common side effect of birth control, especially during the first few months after starting a new method. Any birth control containing hormones can cause breakthrough bleeding, including:

• Oral contraceptives (pills)
• Implants (plastic rod placed under the skin on the upper arm)
• Skin patches
• Vaginal rings
• Intrauterine devices (IUDs)
• Injections
  

Factors that contribute to breakthrough bleeding while on birth control include:

• Hormonal adjustment: When starting a new birth control method or switching between different hormonal contraceptives, your body may need time to adjust to the new hormone levels. This adjustment phase can trigger breakthrough bleeding, especially one to two weeks before the start of your period. Once your body adjusts to the hormonal changes that take place due to birth control, breakthrough bleeding should become less common or stop.
• Inconsistent use: Irregular use of birth control pills or missing pills for a day or two can trigger breakthrough bleeding.
• Uterine lining disruption: Birth control methods containing progesterone or progestin (synthetic progesterone), such as progestin-only oral contraceptives ("the pill"), Depo-Provera injections, or intrauterine devices (IUDs), can alter the uterine lining and cause unpredictable breakthrough bleeding that may be light spotting or heavy bleeding.
  

Withdrawal vs. Breakthrough Bleeding

Withdrawal bleeding occurs during the hormone-free interval of combined hormonal contraceptives, like birth control pills. It happens when you take the placebo pills or have a break between active pill packs. This bleeding mimics a menstrual period and is a response to the sudden drop in hormone levels when you pause or stop taking hormonal birth control.

Breakthrough bleeding is unexpected uterine bleeding that occurs outside the regular menstrual cycle, often seen as spotting or light bleeding. It can happen at any time during the menstrual cycle.

Why Breakthrough Bleeding Happens Around Menopause

Breakthrough bleeding can occur during the transition to menopause (perimenopause). If bleeding occurs after menopause, it's called postmenopausal bleeding. During perimenopause, your body undergoes significant hormonal shifts as it prepares for menopause.

During perimenopause, your ovaries begin to produce less estrogen and progesterone—hormones that regulate your menstrual cycle. These hormonal fluctuations lead to changes in the uterine lining, causing it to thicken and shed irregularly (breakthrough bleeding).

After menopause, the ovaries stop producing eggs, estrogen and progesterone levels drop significantly, and your period stops completely. Postmenopausal bleeding may be light brown or pinkish-gray spotting or heavy flow similar to a period. Several factors can lead to postmenopausal bleeding, including:

• Irritation: Your vaginal and vulvar tissue gets thinner after menopause, making it more likely to bleed in response to friction during sexual intercourse or a pelvic exam.
• Hormone therapy: Sometimes, hormone replacement therapy (HRT) causes the uterine lining to thicken (endometrial hyperplasia), which may lead to breakthrough bleeding.
• Polyps: Non-cancerous growths in the uterus or cervix can sometimes cause bleeding after menopause.
• Cancer: Though rare, endometrial or ovarian cancer can cause postmenopausal bleeding.

Breakthrough Bleeding vs. Regular Period

It can be difficult to differentiate between your regular menstrual period and breakthrough bleeding, especially if you are new to hormonal birth control or experiencing perimenopause. While both involve uterine bleeding, there are some key differences between breakthrough bleeding and a regular period.

Regular Period

Though menstrual cycles can vary from person to person, most have common characteristics, including:

• Timing: Follows a predictable cycle, occurring approximately every 21 to 35 days for most people.
• Duration: Typically lasts three to seven days, with a consistent flow pattern.
• Flow: Starts light, becomes heavier, and then tapers off.

Breakthrough Bleeding

Breakthrough bleeding is less predictable than a regular menstrual period.

• Timing: Occurs at unexpected times in the menstrual cycle, often between regular periods or during the use of hormonal birth control.
• Duration: Typically shorter than a regular period; may be a one-time tinge of blood on your underwear or toilet paper or last for a few hours or a couple of days.
• Flow: May vary from light spotting to heavier bleeding and may have inconsistent flow patterns.
  

Breakthrough Bleeding Risk Factors

Certain factors can increase the likelihood of experiencing breakthrough bleeding, including:

• Starting a new hormonal birth control method
• Changing the dosage or type of hormonal birth control
• Skipping birth control pills or taking them late
• Obesity
• Certain medical conditions, including polycystic ovarian syndrome (PCOS) or endometriosis
• Smoking
• Specific herbs that can thin the blood, including ginkgo biloba, ginger, chamomile, and St. John's wort
  

Breakthrough Bleeding vs. Implantation Bleeding

Implantation bleeding is light spotting or bleeding that occurs when a fertilized egg implants in the lining of the uterus. It typically occurs 10-14 days after ovulation—around the time you would expect your period—and is a common sign of early pregnancy. Implantation bleeding is usually very light, with small amounts of pale pink to rust-colored blood. It may be intermittent or constant but lasts only a few hours up to three days.

Self-Care With Breakthrough Bleeding

While breakthrough bleeding can be an unexpected and unsettling experience, it is often a harmless occurrence you can manage with some self-care practices once a healthcare provider has confirmed the cause of your bleeding. Self-care strategies for managing breakthrough bleeding include:

• Track your cycle: Regularly monitoring your menstrual cycle can help you identify patterns and anticipate the potential occurrence of breakthrough bleeding. Use a calendar, app, or journal to record the dates of your period, breakthrough bleeding, and any associated symptoms.
• Choose appropriate menstrual products: Select those that suit your flow level and preferences. You may opt for lighter products like pantyliners or thin pads during breakthrough bleeding.
• Stress management: Prioritize rest and find activities to help manage stress. This may include getting plenty of sleep, engaging in activities you enjoy (e.g., reading, walking, cycling, spending time with family/friends), and spending time outdoors.
• Eat iron-rich foods: Bleeding can deplete your body's iron stores and lead to fatigue. Incorporating iron-rich foods, such as leafy greens, red meat, and beans, can help replenish iron stores.
• Over-the-counter (OTC) medications: OTC pain relievers like Advil (ibuprofen) or Tylenol (acetaminophen) can help alleviate cramps and discomfort associated with breakthrough bleeding.

Heavy Uterine Bleeding and Symptoms to Discuss With a Provider

While breakthrough bleeding is common and usually not a reason to worry, it is important to see a healthcare provider if you experience breakthrough bleeding and any of the following symptoms:

• Heavy or prolonged bleeding: Heavy breakthrough bleeding requiring frequent pad or tampon changes (every hour for several hours) or lasting for more than a week.
• Severe pain or cramping: Breakthrough bleeding along with pain that interferes with your daily activities.
• Unusual discharge or odor: If breakthrough bleeding is accompanied by unusual discharge, such as a thick, yellow, or green discharge, or has a strong odor, it could be a sign of an infection.
• Unexpected or persistent breakthrough bleeding: Breakthrough bleeding that occurs unexpectedly or persists even after you've adjusted to a new birth control method or transitioned through menopause could indicate hormonal imbalances or an underlying condition.
  

Talk to a healthcare provider if you have concerns or questions about breakthrough bleeding, even if you don't have other symptoms. They can provide reassurance, address your concerns, and offer guidance based on your situation.

Summary

Breakthrough bleeding is unexpected bleeding that occurs between regular menstrual periods. It is a common side effect of hormonal birth control, especially during the first few months of starting a new method. It can also occur during perimenopause due to hormonal fluctuations or during pregnancy when a fertilized egg implants in the uterine lining. See a healthcare provider if you are experiencing breakthrough bleeding that is heavy, prolonged, or accompanied by intense pain or unusual discharge.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

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By Lindsay Curtis
Curtis is a writer with over 20 years of experience focused on mental health, sexual health, cancer care, and spinal health.