ConditionWomen's & pregnancy health
Mittelschmerz (Ovulation Pain)
Mittelschmerz is one-sided lower belly or pelvic pain that happens around ovulation, about 14 days before your next period. The name is German for "middle pain". It affects roughly 1 in 5 people who ovulate. The pain is usually a dull ache or sudden twinge on one side, lasting a few minutes to 48 hours. It is harmless, but severe pain, fever or a possible pregnancy should be checked to rule out appendicitis, an ovarian cyst or an ectopic pregnancy.
Also called: Ovulation pain, midcycle pain, middle pain
At a glance
- What it is
- Pain on one side of the lower belly at ovulation.
- When
- Midcycle, about 14 days before your period.
- How long
- Minutes to 48 hours, usually 6 to 8 hours.
- How serious
- Harmless.
- Treatment
- Heat, over-the-counter pain relief, or hormonal birth control to stop ovulation.
When to get help
Call 911 or go to the ER
- Severe, sudden one-sided pain with fainting, dizziness, shoulder-tip pain or a positive pregnancy test (possible ectopic pregnancy or ruptured cyst)
- Severe pain with vomiting that comes in waves (possible ovarian torsion)
- Pain that moves to the lower right belly and steadily worsens, with fever or loss of appetite (possible appendicitis)
See a doctor within a day or two
- Pelvic pain with fever over 38 °C (100.4 °F), unusual vaginal discharge or pain during sex
- Pain lasting more than 2 to 3 days
- Pain with burning on urination or blood in the urine
Book a routine appointment
- Midcycle pain that is getting worse each month or disrupts work or sleep
- Painful periods, pain with sex or bowel movements as well (possible endometriosis)
Usually safe to manage at home
- A mild ache or twinge on one side midcycle that fades within a day or two
- A small amount of spotting or clear, stretchy discharge at the same time
What causes ovulation pain
Each month a fluid-filled follicle grows on one ovary. As it enlarges it stretches the ovary's surface, which can cause an ache before ovulation. When the follicle ruptures to release the egg, a small amount of fluid and blood spills into the pelvis. This irritates the lining of the belly (peritoneum) and can cause sharper pain for a few hours. Contractions of the fallopian tube may also contribute.
Because ovulation usually alternates between ovaries, the pain may switch sides from month to month, but it can also stay on one side.
Mittelschmerz symptoms
- pain on one side of the lower belly or pelvis
- a dull, cramp-like ache, or a sudden sharp twinge
- timing in the middle of the cycle, about 2 weeks after the first day of your last period in a 28-day cycle
- duration from a few minutes to 48 hours
- sometimes light spotting or a change to clear, slippery, egg-white cervical mucus
- occasionally mild nausea
Is it mittelschmerz or something else?
| Condition | How it differs |
|---|---|
| Appendicitis | Pain often starts around the navel, settles in the lower right, worsens over hours, with fever and loss of appetite |
| Ovarian cyst | Pain may last longer or come on suddenly if the cyst bursts; ultrasound shows the cyst |
| Ectopic pregnancy | Positive pregnancy test, missed or unusual period, bleeding, possible collapse |
| Ovarian torsion | Severe pain with vomiting; emergency |
| Endometriosis | Pain at other times too, especially with periods, sex and bowel movements |
| Pelvic inflammatory disease | Pain on both sides, fever, abnormal discharge |
How it is diagnosed
Mittelschmerz is diagnosed from the timing and pattern of pain. Keep a calendar for 2 to 3 cycles, noting the day pain starts, which side, and how long it lasts. If pain is severe or unusual, a doctor may do a pelvic exam, pregnancy test, urine test, STI swabs and a pelvic ultrasound to rule out other causes.
Treatment and relief
- Heat: a heating pad or warm bath relaxes the muscles.
- Pain relievers: ibuprofen or naproxen work well for cramp-like pain. Acetaminophen (paracetamol) is an alternative. Follow the label dose, and avoid NSAIDs if you have stomach ulcers or kidney disease.
- Hormonal birth control: combined pills, patches, rings or some other methods stop ovulation and prevent the pain. This is worth considering if it is frequent and troublesome.
Ovulation pain and fertility
Mittelschmerz is a natural sign of ovulation and some people use it, alongside cervical mucus changes and ovulation test kits, to identify their fertile window. It is not precise enough to use as birth control on its own. The absence of ovulation pain does not mean you are not ovulating.
Frequently asked questions
What are the symptoms of mittelschmerz?
The main symptom is pain on one side of the lower belly in the middle of the menstrual cycle. It may be a dull ache or a sudden sharp twinge and lasts from minutes to 2 days. Some people notice light spotting, slippery discharge or mild nausea at the same time.
How long does ovulation pain last?
Usually a few hours, often 6 to 8, but it can last from a few minutes up to 48 hours. Pain lasting longer than 2 to 3 days, or getting worse rather than better, should be checked by a doctor.
Can ovulation pain be severe?
It is usually mild, but some people have sharp pain that interrupts daily activities. Severe pain with fainting, vomiting, fever or a positive pregnancy test is not typical of mittelschmerz and needs urgent medical assessment.
Does mittelschmerz mean I am fertile?
It usually means you are ovulating at that time, which is when you are most fertile. Pregnancy is most likely from intercourse in the few days before and on ovulation day. It does not tell you anything about overall fertility.
Why do I get ovulation pain on the same side every month?
Ovulation does not strictly alternate between ovaries, so pain can be on the same side several months running. If it is always on one side, persistent, or worsening, ask your doctor about an ultrasound to check for a cyst or endometriosis.
Sources
This guide was written from current patient and clinical guidance, including:
- American College of Obstetricians and Gynecologists: Chronic pelvic pain
- NHS: Ovulation pain
- MedlinePlus: Mittelschmerz
- Cleveland Clinic: Mittelschmerz
- American Academy of Family Physicians: Evaluation of acute pelvic pain in women