Endometriosis flare-ups: If you know, you know about the debilitating pain it can cause for at least 7-15% of women worldwide. For some people, their endometriosis gets worse around their monthly period, but there are other more sneaky triggers of flare-ups in endometriosis pain, like certain aspects of your diet.

The best way endometriosis sufferer Jacqueline Solivan can describe a flare-up is “The equivalent of tightly twisting a balloon animal into a shape — but the balloons are your organs.” She’s shared how having excruciating internal and back pain that takes her out each month led her to track her triggers and attempt to ward them off ahead of time.

Read on to better understand — and avoid — certain endometriosis triggers and get ahead of the flare-ups as best as you can.

What is an endometriosis flare-up?

Simply put, an endometriosis flare-up is a sudden spike in symptoms — like pelvic pain, bloating, fatigue, or digestive issues — that goes beyond your usual baseline. These episodes are thought to stem from inflammation and nerve involvement, often triggered by hormonal changes, stress, or other factors, though sometimes they appear without warning.

Endometriosis involves tissue that’s similar to the lining of the uterus, or endometrial tissue, growing outside of the uterus. Once that tissue has formed outside the uterus, the symptoms can be exacerbated by inflammatory changes (keep reading for the common triggers of inflammation and therefore endometriosis flare-ups), or by the development of scarring in the tissue that can become irritated and increase pain, explains Dr. Ryniec. Because the tissue is growing outside of the uterus and causing tenderness and inflammation, it can alter your anatomy and cause issues in other systems, such as bowel and bladder dysfunction and pain, Dr. Ryniec adds.

When does endometriosis flare up?

Endometriosis flare-ups most often happen around your period, when hormone shifts fuel inflammation and pain, but they can happen at other times, too.

“A hallmark of endometriosis is pain with menstruation, but there can be pain or flare-ups at other times in the cycle as well,” says Jessica Ryniec, MD, a Boston-based double board-certified OB/GYN and reproductive endocrinologist. For example, Solivan shares that though she has very heavy, uncomfortable periods (the kind that causes you to continuously go through a super-plus tampon and an overnight pad), her flare-ups of most intense pain typically happen around ovulation.

Research shows that estrogen plays a key role in driving endometriosis activity, which is why symptoms often intensify during times of hormonal fluctuation. That said, flare-ups don’t follow the same pattern for everyone. For some, pain is cyclical; for others, it’s unpredictable and can show up anytime, with no obvious trigger.

Can you get an endometriosis flare-up without a period?

Absolutely, endo flare-ups aren’t limited to menstruation — flare-ups can also strike mid-cycle around ovulation, or at other times if triggered by things like stress, illness, diet, or even certain types of exercise.

How long do endometriosis flare-ups last?

Endometriosis flare-ups don’t have a set timeline — they can last a few hours, a couple of days, or sometimes stretch into weeks. For many, flares are tied to their menstrual cycle and peak around periods or ovulation, but they can also linger due to ongoing inflammation, stress, or other triggers.

Research highlights that chronic pelvic pain in endometriosis is often cyclical but can also be continuous, with flares that vary in both intensity and duration from person to person. This unpredictability is part of what makes endo so challenging: a flare might ease with rest and pain relief, or it might hang around and interfere with daily life until hormone levels shift again.

What are endometriosis flare-up symptoms?

Flare-ups can vary for each person, especially depending on their timing in the menstrual cycle. Some of the most common symptoms include the following, according to Dr. Ryniec:

  • Heavy menstrual bleeding
  • Urinary urgency and frequency
  • Low back pain
  • Diarrhea, constipation, nausea, vomiting, or bowel cramping
  • Chronic fatigue or lack of energy
  • Pain with vaginal penetration

What causes endometriosis flare-ups?

Endometriosis flare-ups are thought to be caused by a mix of inflammation, immune system changes, and nerve sensitivity. When endometrial-like tissue grows outside the uterus, it releases inflammatory chemicals (called cytokines) that irritate nearby nerves and organs, making pain more intense during a flare.

Another factor is how the immune system responds. Research shows that people with endometriosis may have altered immune function, which can make the body less effective at clearing the misplaced tissue and more prone to chronic inflammation. This ongoing inflammation can then be amplified by hormonal fluctuations, leading to the unpredictable flare-ups many experience.

Endometriosis flare-up triggers

Flare-ups don’t come out of nowhere — they’re often set off by specific triggers that fuel inflammation, hormone shifts, or both. While everyone’s body is different, some common culprits stand out:

  • Chronic stress: One of the most well-known inflammatory triggers for endometriosis.
  • Poor sleep: Sleep and endometriosis pain also have a “chicken-or-egg” relationship. Pain can keep you up at night, but disrupted sleep is also known to raise inflammatory markers in the body, which can make endometriosis symptoms worse, says Dr. Ryniec.
  • Dietary inflammation: Foods high in sugar, processed ingredients, or red and processed meats are considered inflammatory and can worsen flare-ups. “Foods that tend to be inflammatory can increase your overall systemic inflammation and cause more pain in the body,” explains Dr. Ryniec.
  • Alcohol: Drinking significant amounts is known to raise estrogen levels, which can drive endometriosis activity. “Since endometriosis flares can be mediated by estrogen, there is an increased risk of flares,” says Dr. Ryniec. Chronic heavy drinking can also weaken immune function, ramping up both inflammation and pain.

Can stress cause endometriosis pain?

Abslutely — in fact, chronic stress is of the most prominent inflammatory triggers of endometriosis flare-ups. But it’s kind of a chicken-or-egg situation. “There is a link between elevated stress and higher pain levels and worsening of chronic medical conditions in general, but it's tough to know whether this is related to the body's reaction to stress or the hormones that are released or altered in times of stress,” says Dr. Ryniec. “It also probably goes in both directions, where stress can cause flare-ups, and flare-ups can increase stress,” she says.

What makes endometriosis worse?

Beyond the well-known flare-up triggers like stress, diet, and sleep, certain factors can make endometriosis symptoms more intense or harder to manage over time.

  • Scar tissue and adhesions: Endometriosis can lead to adhesions — bands of scar tissue that bind organs together. These can cause chronic pelvic pain and make flare-ups more severe by limiting organ movement.
  • Delayed diagnosis: On average, it takes 7–10 years to get an endometriosis diagnosis. That’s years of unmanaged inflammation and tissue growth, which may increase pain severity and lead to complications like infertility. But there’s good news: non-invasive tools like the MyReceptiva test can help speed up the process and uncover hidden inflammation earlier.
  • Hormonal fluctuations: Because endometriosis lesions respond to estrogen, anything that increases estrogen exposure — like certain medications or conditions that alter hormone balance — can intensify symptoms.
  • Co-existing conditions: People with endometriosis are more likely to also experience conditions like irritable bowel syndrome (IBS), interstitial cystitis (painful bladder syndrome), or fibromyalgia. These overlapping pain syndromes can heighten the overall experience of flare-ups and fatigue.
  • Environmental and lifestyle factors: Exposure to endocrine-disrupting chemicals (like dioxins) has been linked to worsening disease activity in some studies, though research is ongoing).

Endometriosis flare-up treatment: Is it possible?

Once you get an endometriosis diagnosis (which can take up to 10 years, by the way), it’s a good idea to look for patterns in your personal endometriosis triggers and try to avoid or minimize those triggering foods or habits. Sometimes you can’t help it and don’t sleep well or eat foods that end up bothering you, though. Dr. Ryniec suggests working with an endometriosis specialist if there is one in your area, who can help craft a treatment plan for your case of endometriosis. Here are some general rules of thumb in avoiding endometriosis triggers as best as you can:

Manage stress and your sleep habits

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One great strategy for consistently managing stress is working on cognitive behavioral therapy (CBT), a therapy technique that helps you shift negative thought patterns to more manageable or productive ones, Dr. Ryniec suggests. Part of the stress puzzle is practicing good sleep hygiene (that means no scrolling on your phone in bed!) and prioritizing a solid sleep routine, she adds.

Keep a food diary

Solivan recommends keeping a log of all the foods you eat, and looking for patterns—she’s found that dairy and sugar have led to flare-ups in general and has learned to stay away from them as much as possible (she substitutes refined sugar with coconut sugar when cooking or baking).

Watch out for your trigger foods

Once you know the foods that contribute to an endometriosis flare-up (which can include bowel dysfunction), you can try to get ahead of it by cutting back on those foods. “Consider adding anti-inflammatory foods or supplements to your diet,” says Dr. Ryniec. For Solivan, that looks like eating mostly plant-based and staying away from the more inflammatory animal proteins as much as possible — but not everyone can go fully vegetarian or vegan and cut out animal products from their diet altogether.

Move your body

“Regular physical activity may help through reduction of inflammation and release of endorphins; it also may be beneficial to prevent muscle tension, which can worsen symptoms,” says Dr. Ryniec. On days when she’s able to stretch and doesn’t feel too tight, Solivan tries to do some stretching, walking on a walking pad, and somatic exercises like barre and yoga. On other days, walking can feel like too much pressure on her lower back. But when she focuses her energy on a combination of these types of movement, cutting back on inflammatory foods, and tempering stress, she can go two months without an endometriosis flare-up, she says.

Endo flare-ups don’t have to dictate your life

Endometriosis flare-ups can feel unpredictable, overwhelming, and at times isolating — but knowing your triggers and patterns is a powerful first step in managing them. From stress and sleep to hormones and co-existing conditions, there are many factors that can make endo worse, and no two people’s experiences are exactly alike.

The key is to listen to your body, track what sets off your symptoms, and work with a provider who understands the complexities of endometriosis. While diagnosis can take years, newer non-invasive options are helping to speed up that process. The MyReceptiva test is one such tool, already used by tens of thousands of people, that can detect hidden inflammation without surgery — giving you clearer answers, sooner. Because the sooner you know what’s going on, the sooner you can take steps to find relief.

Ready to try it? Use code RESCRIPTED to get $85 off your MyReceptiva Testing Kit today!

Mara Santilli is a journalist reporting on health and wellness and how social and political systems influence the well-being of certain groups, including but not limited to Black and brown communities, women, and the LGBTQ+ community. Her editorial work has appeared in publications such as Shape, Marie Claire, Cosmopolitan, Women’s Health, InStyle, Glamour, and more. Outside of reading and writing, she enjoys traveling (especially to Italy), singing, dancing, musical theatre, and playing guitar and piano.