Mittelschmerz: If you've never heard the term, you may think its only link to your menstrual cycle is beginning with the same letter of the alphabet. A German word that translates to “middle pain,” it’s a very literal description of the one-sided, lower abdominal pain that can occur midway through the menstrual cycle.
By some counts, mittelschmerz — also known as ovulation pain — affects approximately 40% of people with ovaries of reproductive age. Some people experience it each month, some never at all, and others fall somewhere in the middle.
If you’re intrigued or wondering if you’ve ever experienced mittelschmerz, let us tell you more about this common and usually harmless sensation:
- Ovulation is the brief period (just 1-2 days) during the menstrual cycle when an egg is released from an ovary. (It's also one day in your six-day fertile window.)
- Ovulation pain, or mittelschmerz, is pain in the side of your lower abdomen that occurs around the time of the month when you’re ovulating. Some people experience it each month and others never at all.
- Mittelschmerz likely occurs for one of two reasons: Either it’s the egg stretching the surface of the ovary as it develops and prepares for ovulation, or it’s the release of blood and cystic fluid when the follicle ruptures which can irritate the abdominal lining.
- Ovulation cramps may feel similar to menstrual cramps, but you can determine the difference by the location of the pain and when they occur in your cycle.
Now that you've got the big picture of mittelschmerz, let's dive into the details.
What's ovulation again?
The menstrual cycle is broken into phases: follicular (when menstrual periods happen and ovarian follicles, which house eggs, develop), ovulation, and luteal. The length of each phase varies by person, but ovulation is always the shortest phase — lasting just 1-2 days of your monthly cycle (i.e., day 14 of a 28-day menstrual cycle). The five days before and the day of ovulation are considered the "fertile window" because having sex as close to ovulation as close as possible increases the chance of pregnancy.
Ovulation is triggered about 24-48 hours after elevated blood levels of a hormone called luteinizing hormone (LH) (the hormone ovulation predictor kits measure) — a hormonal surge that encourages the release of an egg from an ovary into the fallopian tube. From there, the egg has two potential paths:
- If it's fertilized, the egg and sperm form a zygote which travels down the fallopian tube to the uterus where it implants in the lining of the uterus. This is the start of pregnancy.
- If it isn’t fertilized by sperm, the egg will disintegrate and leave the body (along with the rest of the lining of the uterus) during the menstrual flow.
If you’re still curious about the ins and outs of ovulation, one of Modern Fertility's clinical product scientists published a more in-depth explanation of exactly how your hormones change before, during, and after that egg's release.
Why do people get cramps during ovulation?
The exact cause of the mittelschmerz is still uncertain, but there are two things that happen during the process which likely cause painful ovulation for some people:
- As the egg develops and prepares for ovulation, it stretches the surface of the ovary which can cause discomfort.
- Once the ovarian follicle (the fluid-filled sac that houses and develops eggs) actually ruptures, it releases blood or cystic fluid (along with the egg, of course) which can irritate the abdominal lining.
"I typically describe ovulation as a surprisingly violent phenomenon that occurs. While at such a micro level, the egg explodes out of the ovary," says OB-GYN and Modern Fertility medical advisor Dr. Eva Luo, MD, MBA, FACOG. "It's no wonder that some individuals can feel that they have ovulated and/or feel pain."
Not everyone with ovaries experiences mittelschmerz; and even if you do, it might not be each month. The pain typically dissipates within a day, so most people don’t require treatment — but there are remedies that can help assuage the discomfort. A warm bath, heating pad, or over-the-counter (OTC) nonsteroidal anti-inflammatory medication (think ibuprofen, naproxen or Aleve) are all recommended.
"If pain is so uncomfortable that OTC pain medications are not managing the pain, and if it continues for more than a few days, definitely consult with a physician on a much broader evaluation," advises Dr. Luo. If the pain is isolated to ovulation, your provider may prescribe the birth control pill (or other form of hormonal contraception like the patch or ring) to prevent ovulation — but you’ll want to make sure this method aligns with any plans for kids.
Is cramping during ovulation the same thing as PMS?
Ovulation cramps can feel pretty similar to premenstrual syndrome (PMS) period pain, but, alas, they’re different sources of pain occurring at different times of the month. Here’s how to help understand which is which:
Can cramping during ovulation indicate something else is going on?
Although a pain (literally), ovulation cramps are generally harmless and not an indicator of an underlying issue or reason for concern. However, if something doesn’t seem right — let’s say the pain becomes really severe or lasts longer than a day — consider booking an appointment with your healthcare provider.
In some cases, severe and sharp pain in the abdomen could mean something more serious, like appendicitis or an ectopic pregnancy (when a fertilized egg implants outside the uterus, such as in the fallopian tube). The pain could even represent something that could cause issues with fertility, like endometriosis, a sexually transmitted infection (STI), or pelvic inflammatory disease (PID, which can be caused by untreated STIs), so don’t hesitate to get it checked out.
The bottom line on mittelschmerz
Ovulation cramps, or mittelschmerz, is pain that naturally occurs around the time of the month when you’re ovulating. Not to be confused with menstrual cramps, ovulation pain is one-sided, hovers in your abdominal area or lower back, and usually lasts for minutes or hours (two days at the very max). It’s pretty common and results from an egg preparing for ovulation or rupturing from the follicle — resulting in irritation and discomfort.
Some claim that mittelschmerz can help you understand when you’re ovulating, but ovulation tests (like the Modern Fertility Ovulation Test!) provide a science-backed view into ovulation and your fertile window.
Just for fun: Another ovulation "sign"?
Since this article tackled the sometimes painful side of ovulation, we thought we'd wrap things up with the other side of the equation: some of the reported feel-good signs or symptoms of ovulation.
Is feeling more attractive during ovulation really a thing? One study from 2012 asked participants (a mix of men and women) to analyze photos of the faces of 20 young women during different phases of their cycle. According to the authors, the participants reported that ovulatory faces were more attractive, healthy, sexy, sociable, trustworthy, young, and likeable than luteal faces.
While there’s limited science to back those attraction claims, there is some early evidence to suggest that ovulation might impact flirtation and dating behaviors:
- One study found that women tended to show a greater preference for socializing and competitiveness in males on fertile days versus non-fertile days.
- In another small study, women reported being more attracted to someone other than their primary partner on their fertile days; they also commented that their primary partners seemed more attentive during their fertile window.
The more you know.
This article was medically reviewed by Dr. Eva Marie Luo, MD, MBA, FACOG, an OB-GYN at Beth Israel Deaconess Medical Center and Clinical Lead for Value at the Center for Healthcare Delivery Science at Beth Israel Deaconess Medical Center.