Endometriosis Flare-Up Relief: What to Do, What Helps and When It Is an Emergency

What a flare is

Researchers define a flare as symptoms that are much worse than usual for you. In a 2026 BJOG survey of 236 people with endometriosis, 98% had experienced flares, and the typical respondent spent about 96 hours a month in a flare (Coxon et al., 2026). Flares came in three lengths: short flares under an hour, medium flares lasting up to a day, and long flares lasting more than a day. Long flares were the most common, reported by 85.6%, with a median length of three days (Coxon et al., 2026).

A flare is rarely one symptom. Women describe a cluster: cramping or stabbing pelvic pain, pain that spreads to the lower back and legs, a swollen and tender abdomen, nausea, painful bowel movements or urination, heavy fatigue, and a foggy or low mood. Which symptoms dominate depends on where your disease is and on how sensitized your nervous system has become over the years.

Flares are also common in pelvic pain without a confirmed endometriosis diagnosis. In an Oxford cohort of 100 women with chronic pelvic pain, 76% had experienced flares, and more than 60% said flares stopped them doing their usual activities (Coxon et al., 2024).

Triggers reported in studies, and how strong the evidence is

Only about half of women can name a trigger. In the 2026 survey, 52.8% could identify one (Coxon et al., 2026). The triggers named most often for long flares were the menstrual cycle, fatigue and stress. Medium flares were linked to standing for a long time or doing more physical activity than usual. Short flares followed sex, internal examinations such as smear tests and vaginal ultrasounds, and bumpy movements (Coxon et al., 2026).

These are self-reports, not controlled experiments, so treat them as patterns to test against your own log rather than rules. Menstruation and ovulation are the triggers with the clearest biological basis, because lesions respond to the same hormones as the uterine lining. Pain with bowel movements and with sex are recognized symptoms of the disease itself, listed by the WHO and the NHS, so a flare after either is a symptom pattern, not a sign you did something wrong (WHO; NHS).

Food is the least settled area. In an Australian survey of 484 women, dietary changes were rated 6.4 out of 10 for pain relief by those who tried them, and 53.8% of women who used alcohol to cope reported side effects from it (Armour et al., 2019). The ESHRE 2022 guideline reviewed the evidence and made no recommendation for any specific diet or non-medical intervention (ESHRE, 2022). A food diary may help you find a personal trigger. No diet has been shown to treat endometriosis.

First-line relief and the evidence behind it

• Heat. A heating pad, hot water bottle or warm bath on the lower abdomen and back. Heat was the most used self-management strategy in the Australian survey, chosen by 70% of women and rated 6.5 out of 10 for relief (Armour et al., 2019). In a review of six trials in period pain, heating pads reduced pain more than painkillers alone (Jo and Lee, 2018). Those trials were in primary dysmenorrhea, not endometriosis, so the benefit is likely but not proven for flares.
• Anti-inflammatory painkillers, taken early. The NICE NG73 guideline recommends a short trial of paracetamol (acetaminophen) or an NSAID such as ibuprofen or naproxen, alone or together, as first-line pain management (NICE NG73). NSAIDs work on the prostaglandins that drive cramping, so they work better taken at the first sign of a flare than at its peak, and with food. A Cochrane review of 80 trials in period pain found NSAIDs clearly beat placebo, with a higher rate of stomach side effects (Marjoribanks et al., 2015). In endometriosis specifically the trial evidence is thin: one small study of 24 women, rated very low quality (Brown et al., 2017). Check with your doctor before using NSAIDs if you have kidney, stomach or asthma problems or take blood thinners, or if you are or might be pregnant.
• TENS. A transcutaneous electrical nerve stimulation unit on the lower abdomen or back. A Cochrane review found high-frequency TENS reduced period pain in several small trials, while low-frequency TENS had insufficient evidence (Proctor et al., 2002). It is drug-free and can be used alongside painkillers.
• Pelvic floor relaxation and slow breathing. Pain makes the pelvic floor clench, and a clenched pelvic floor hurts more. Lie on your side or back with knees supported, breathe slowly into the belly, and let the pelvic floor drop on each out-breath. Meditation or breathing exercises were used by 47% of women in the Australian survey (Armour et al., 2019). The evidence is limited but the risk is very low, and a pelvic floor physical therapist can teach the technique.
• Rest, then gentle movement. About 80% of women rest during a flare (Coxon et al., 2026). Once the peak passes, light movement helps. A Cochrane review of 12 trials found exercise reduced period pain by about 25 points on a 100-point scale, with low-quality evidence (Armour et al., 2019, Cochrane). Keep it gentle: 34.2% of women in the Australian survey reported that exercise worsened symptoms at some point (Armour et al., 2019). A short walk or stretching, not a hard workout, is the goal during a flare.
• Hydration and bowel care. There are no trials of fluids for flares. Water and a regular bowel habit matter because constipation and a full, irritated bladder both press on painful pelvic tissue. Warm drinks also count as heat.

When a flare is an emergency

Most flares are miserable but not dangerous. A few patterns are not flares at all and need same-day care. Seek emergency care if any of these apply.

Emergency signs

• Sudden, severe pelvic pain on one side, especially with nausea and vomiting. This can mean an ovarian cyst has ruptured or the ovary has twisted on its blood supply (torsion), both of which can happen with endometriomas (MedlinePlus, ovarian cysts).
• Fever with pelvic or abdominal pain. Fever is not part of a typical flare and can signal infection or a surgical problem.
• Fainting, feeling faint, a racing heart or shortness of breath. These can indicate internal bleeding.
• You cannot pass stool or gas, your abdomen is swollen and stays swollen, or you keep vomiting. These are warning signs of a bowel obstruction, which bowel endometriosis and adhesions can cause (MedlinePlus, intestinal obstruction).
• Vaginal bleeding far heavier than your normal period, or heavy bleeding with dizziness.
• Severe pain if there is any chance you are pregnant.

What to log during a flare

Flares are invisible by the time you reach the clinic. In the 2026 survey, 82% to 91% of women did not contact a healthcare provider during a flare, and only 35.3% had ever received advice about flares from a clinician (Coxon et al., 2026). A written record closes that gap. For each flare, note:

• When it started and when it ended, so you know how long your flares really last.
• Pain at its worst on a 0 to 10 scale, and where it was: pelvis, back, legs, rectum, bladder.
• Cycle day, and whether you were bleeding or ovulating.
• What happened in the 24 hours before: sex, a bowel movement, stress, poor sleep, standing for a long time, exercise, a particular food.
• Each medication with the time taken and what the pain score was one to two hours later.
• What else helped or did not: heat, TENS, rest, a bath.
• What the flare cost you: work or school missed, plans cancelled, an emergency visit.

When to call your specialist

Flares that are getting more frequent, longer or more intense are a reason to call, not to cope quietly. So is a new symptom, such as pain with sex, blood in stool or urine, or leg pain. NICE NG73 advises referral to a gynecology or specialist endometriosis service when initial pain management is not working or symptoms are severe, persistent or recurrent (NICE NG73). NICE suggests a trial of around three months of simple painkillers; if that, or a hormonal treatment, has not helped or was not tolerated, ask about referral.

Call sooner if you are relying on an emergency department for pain control, need opioid painkillers to function, or are missing work or school. Bring your flare log. Logged in the PelviQuest app, those entries become a dated record your doctor can read before the visit; the app is a screening and tracking aid, not a diagnosis.