PMDD or endometriosis: how to tell them apart

PMDD is a mood disorder tied to your menstrual cycle. It's listed in DSM-5-TR and ICD-11, and it means at least five symptoms, including one mood symptom like irritability, anxiety or low mood, show up only in the week before your period and ease within a few days of it starting.

Endometriosis is a physical condition. Tissue similar to the lining of the uterus grows outside it, often on the ovaries, fallopian tubes or pelvic lining, and causes inflammation and pain. That pain can show up any time in your cycle, not just the week before your period, though it often gets worse then too.

The simplest way to separate them: PMDD is defined by when mood symptoms happen and when they stop. Endometriosis is defined by where tissue grows and the pain or bleeding it causes, which can continue well beyond the days before your period. Learn more about PMDD.

Yes. PMDD and endometriosis come from different mechanisms, so one doesn't rule out the other. PMDD is about how your brain reacts to the normal drop in estrogen and progesterone before your period. Endometriosis is about where uterine-like tissue ends up growing.

A study of women with migraine found that having endometriosis didn't change how often PMDD symptoms showed up (Headache, 2007). That suggests the two conditions can sit side by side without one causing the other.

If you have both, the week before your period can bring pain and mood symptoms together, which can feel like a lot some months. Naming each part separately, this is the pain flaring, this is the mood drop, can make it easier to know what you're dealing with and what might help.

Both conditions can bring symptoms that look similar from the outside, especially in the days before a period:

• Pelvic or abdominal discomfort
• Fatigue or low energy
• Low mood or irritability
• Trouble concentrating
• Changes in sleep

In GP records of adolescents, dysmenorrhea was coded in 3.48% of cases, pelvic pain in 0.63% and premenstrual syndrome or PMDD in 0.22%, low rates that likely reflect under-coding of these symptoms rather than how often they actually occur (British Journal of General Practice, 2024).

The overlap is mostly in the physical and energy symptoms. What usually doesn't overlap is the timing: endometriosis pain can turn up at any point in the cycle, while PMDD's mood symptoms are confined to the final week before bleeding and clear soon after it starts. See how PMS and endometriosis interact.

Diagnosis methods differ because the conditions are different kinds of problems.

For PMDD, there's no scan or blood test. A doctor looks for a pattern: five or more symptoms, one of them a mood symptom, that show up in the week before your period and are minimal the week after, confirmed with daily ratings over at least two cycles.

For endometriosis, a doctor usually starts with a pelvic exam and ultrasound, and may use an MRI or laparoscopy to confirm lesions and see how extensive they are. Pain that doesn't fully go away after your period, pain during sex, or pain with bowel movements point more toward endometriosis than PMDD.

Because only around 0.07% of adolescent girls in one large GP dataset had documented endometriosis, far fewer than the 3.48% with coded dysmenorrhea, it's often missed or delayed for years (British Journal of General Practice, 2024). Bringing a clear symptom pattern to the appointment helps a doctor sort out which one fits. Read how to get a PMDD diagnosis or find a PMDD specialist.

A daily chart is the clearest way to separate these two conditions, because it shows the shape of your month instead of just the worst days.

Each day, you note your mood, pain level and any physical symptoms, for at least two full cycles. The Daily Record of Severity of Problems (DRSP) chart is built for exactly this.

If your symptoms spike hard in the final week before your period and drop to near nothing within days of it starting, that pattern fits PMDD. If pain shows up throughout the month, even if it's worse premenstrually, that points toward endometriosis or a condition made worse by your cycle, known as premenstrual exacerbation.

Niyora is a PMS and PMDD support app. If you want help noticing when symptoms tend to cluster, its estimated PMS window can show you where you are in your cycle while you track, so the pattern is easier to see.

Bring the finished chart to your appointment. It gives your doctor something concrete to work from instead of a memory of a bad week.

Treatment follows the diagnosis, so it isn't interchangeable.

For PMDD, guidelines point to SSRIs, which can work even when taken only in the second half of your cycle, some hormonal contraceptives, and CBT. A doctor decides which fits your situation.

For endometriosis, treatment often starts with pain relief and hormonal therapy to suppress periods and calm lesion activity. Progestins, including dienogest, have been studied in at least 19 randomized trials for endometriosis pain. The same 2025 systematic review found none for PMS pain specifically, so there's no trial evidence yet for progestins as a PMS pain treatment (Archives of Gynaecology and Obstetrics, 2025). Hormonal contraceptives are used for both conditions, which is part of why they can look similar from the outside (European Journal of Contraception & Reproductive Health Care, 2024). For some people with confirmed lesions, laparoscopic surgery brings a lasting drop in pelvic and premenstrual pain, with benefits still holding at two years in one large cohort study (BMJ Open, 2018).

Trial quality across these gynecological conditions is still uneven: an early (not yet peer-reviewed) review found only 7% of trials were low risk of bias (Research Square preprint, 2026), so a doctor's judgment matters as much as any single study.