Braxton Hicks contractions are your uterus practicing for labor. They’re irregular tightenings of the uterine muscle that don’t cause your cervix to open or thin out, and they’re a normal part of pregnancy. If you’re feeling your belly periodically harden and then relax, that’s almost certainly what’s happening.
What’s Actually Happening in Your Body
During a Braxton Hicks contraction, the muscle fibers of your uterus tighten briefly and then release. You’ll feel your belly become firm or hard to the touch, sometimes for up to a minute, before softening again. Some providers believe these contractions help prepare the cervix for labor by gradually softening it, though the key distinction is that Braxton Hicks do not cause your cervix to dilate or efface. Only real labor contractions do that.
Think of them as a rehearsal. Your uterus is a muscle, and like any muscle, it contracts. These practice rounds help it get ready for the sustained, powerful contractions it will need during delivery.
When They Start and What They Feel Like
Braxton Hicks can begin as early as the second trimester, though many women don’t notice them until the third trimester when they tend to become more frequent. Some women feel them as a noticeable tightening or squeezing across the belly. Others describe mild pressure or a sensation like the baby is balling up. And some women never feel them at all, even though the contractions are still occurring.
They typically happen only once or twice an hour, a few times a day, and each one usually lasts less than a minute. They don’t follow a predictable pattern, and the intensity stays roughly the same rather than building over time.
Common Triggers
Dehydration is the single most common cause of Braxton Hicks. Even mild dehydration can set them off. Physical activity, lifting, being on your feet for long stretches, a full bladder, and sexual intercourse can all trigger them too. Sometimes they happen for no identifiable reason.
If you notice a pattern, like contractions starting every time you’ve been busy and haven’t had enough water, that’s a strong clue that what you’re feeling is Braxton Hicks rather than something more concerning.
How to Tell Them Apart From Real Labor
The core difference is rhythm. Real labor contractions come at regular intervals, get progressively closer together, last longer, and grow more intense over time. Braxton Hicks are irregular, don’t intensify, and typically fade on their own.
Location matters too. Braxton Hicks are usually felt across the front of your belly. Real labor contractions often start in your lower back and wrap around to the front, or radiate downward with increasing pelvic pressure.
The simplest test is to change what you’re doing. If you’ve been active, sit or lie down. If you’ve been sitting, stand up and walk around. Drink a few large glasses of water. Braxton Hicks will typically ease up or stop within a short time after you rehydrate and shift position. Real contractions won’t care what you do. They keep coming.
How to Get Relief
Since dehydration is the top trigger, drinking water is the first and most effective response. At UT Southwestern Medical Center, when women come in unsure whether they’re in labor, the clinical team checks the cervix and then has them drink several large cups of water in a short window. If the contractions are Braxton Hicks, they stop fairly quickly once the body is rehydrated.
Beyond hydration, try changing your position. If you’ve been on your feet, rest. If you’ve been resting, a short walk can sometimes break the cycle. A warm (not hot) bath can also help the uterine muscle relax. If you’ve been doing physical work or lifting, give yourself permission to stop and rest. Pregnant women who need to move or lift more than usual are especially prone to these contractions.
When Contractions Signal Something Else
Braxton Hicks are harmless, but contractions before 37 weeks that don’t behave like Braxton Hicks need immediate attention. Call your midwife, doctor, or hospital right away if you experience any of the following before 37 weeks:
- Contractions more than four times an hour
- Blood or fluid leaking from your vagina
- A dull, persistent ache in your lower back
- Pelvic pressure that feels like the baby is pushing down
- Cramping that feels like period pain
- Nausea, vomiting, or diarrhea alongside contractions
These can be signs of preterm labor, which is when contractions start to cause the cervix to open too early. The key pattern shift to watch for is contractions that become regular, more frequent, and more intense over time rather than fading away. Braxton Hicks stay sporadic and mild. Real labor builds.
After 37 weeks, the same escalating pattern is simply a sign that labor is beginning, which is exactly what your body has been rehearsing for.