Why You Get Side Stitches When Running, and How to Stop Them

If a sharp pain in your side has ever cut a run short, you have had a side stitch. They are common and frustrating, and most runners have no idea what triggers them or how to make them stop. Below, we clear that up: the cause, the quick relief, and how to prevent them.

What a side stitch is

A side stitch is a sudden pain in the side of your abdomen, usually just below the ribs, that comes on during exercise. Doctors call it exercise-related transient abdominal pain, or ETAP. Runners also know it as a side cramp or a subcostal ache.

It can feel different from one runner to the next. A mild stitch feels like a cramp or a dull ache in your side. A stronger one turns sharp or stabbing, bad enough to break your stride, and it often gets worse when you breathe in or push the pace. Most of the time it strikes one side, more often the right.

Side stitches are one of the most common complaints in running. About 70 percent of runners get at least one in a given year, and roughly one in five suffer during any single race. They show up most in sports with repeated up-and-down torso movement, like running or horse riding.

They are also, in almost every case, completely harmless. A stitch is not an injury and does not signal anything wrong with your body. A normal stitch eases within minutes of slowing down and disappears at rest.

But if a pain in your side is severe, sticks around after you stop, returns while you are resting, or comes with symptoms like nausea or fever, it is not a routine stitch, and it is worth seeing a doctor.

What causes side stitches

For years, the popular explanation was that the diaphragm, the muscle under your lungs, was cramping from a lack of blood. That idea has largely fallen out of favor, since stitches also happen at gentle efforts and ease too quickly to fit it.

The leading explanation today points to the parietal peritoneum, the thin membrane lining the inside of your abdominal wall. Your stomach and other organs hang from it by connective tissue.

With every footstrike, those organs jolt downward and tug on the membrane, and when the friction and stretching build up, the membrane becomes irritated and sends out that sharp, familiar pain.

Several things make a stitch more likely:

• Eating or drinking too close to a run. A full stomach pulls harder on the membrane and rubs against it.
• Sugary or concentrated drinks. These empty from the stomach slowly and raise the pressure inside, which makes stitches worse than plain water does.
• Shallow, chest-based breathing. It limits how much your diaphragm moves and adds strain.
• Poor posture. Slouching through the middle of your body increases the pull on the membrane.
• A weak core. Less support for your organs means more movement and more irritation.
• Doing too much, too soon. Beginners feel them most while their bodies adjust to the pounding.

How to get rid of a side stitch mid-run

When a stitch hits, you can usually run it off within a minute or two. Try these:

1. Slow down or walk. Easing your pace takes the strain off the membrane and often settles the pain on its own.
2. Breathe deep into your belly. Slow, full breaths that push your stomach out calm the irritation better than quick, shallow ones.
3. Press on the spot. Push your fingers into the painful area and lean forward slightly as you keep moving. The pressure and the bend both ease the pull.
4. Exhale as the opposite foot lands. If the stitch is on your right, breathe out each time your left foot hits the ground, and the reverse for a left-side stitch. This shifts the rhythm away from the sore side.
5. Purse your lips and blow out hard. A few forceful exhales through pursed lips can release the tension.
6. Stretch the side. Raise the arm on the painful side overhead and lean gently the other way for a few steps.

If none of it works and the pain keeps building, stop and walk until it clears. Pushing through a bad stitch only drags it out.

Does the side of the stitch mean anything?

Stitches show up more often on the right, sometimes tied to the liver, the largest organ on that side, and the ligaments that hold it. A left-side stitch is often linked to the stomach, which can explain why eating beforehand brings one on.

In practice, the side tells you little about the cause. The same steps work either way: slow down, breathe deep, and press on the spot.

Do side stitches go away as you get fitter?

For most runners, yes. Side stitches are most common in beginners and younger athletes, and they grow less frequent with training.

As you run more, your core gets stronger and holds your organs more steadily, so there is less tugging on the membrane. Your posture and breathing improve with practice, which both help. And you learn your own triggers, like eating too close to a run, and start to avoid them without thinking.

How to prevent side stitches

You cannot rule stitches out entirely, but a few habits can make them rare:

• Leave time after eating. Finish meals about two to three hours before you run, and go easy on large drinks right before.
• Skip sugary drinks pre-run. Water or a diluted sports drink goes down easier than a concentrated, sugary one.
• Warm up and start easy. Easing into a run lets your body adjust before you ask it for pace.
• Breathe deeply and evenly. Belly breathing, which we cover in our guide to breathing while running, keeps your diaphragm working smoothly.
• Build your core. Stronger abdominal muscles hold your organs steadier and cut down on the tugging.
• Stand tall as you run. Good posture through your torso reduces the strain on the membrane.
• Progress slowly. If you are new, add distance and pace gradually while your body toughens up.

Stitches rarely disappear for good, even for elite runners, who still get the occasional one. What changes is that they become the exception, no longer a regular feature of your runs.

Frequently asked questions

Why do I get a side stitch every time I run?

Frequent stitches usually point to a habit you can change: eating or drinking too close to your run, shallow breathing, weak core muscles, or starting too fast. Most runners who get them often can cut them down by adjusting one or two of these.

Are side stitches dangerous?

No. A normal side stitch is harmless and fades within minutes of slowing down. It becomes worth a doctor's visit only if the pain is severe, lingers after you stop, returns at rest, or comes with symptoms like nausea or fever.

Can I still run with a side stitch?

Usually, yes. A side stitch is harmless, so you can keep going at an easy pace while you work it out with deep breathing and pressure on the spot. If the pain is sharp enough to change how you move, drop to a walk until it passes, then ease back in.

Why do I get a stitch under my ribs when I run but not when I walk?

Because running jolts your organs far more than walking does. With every stride you have a moment when both feet leave the ground, and the landing tugs harder on the membrane inside your abdomen. Walking keeps one foot down and stays smooth, so it rarely irritates that membrane enough to hurt.

How do you get rid of a side stitch fast?

Slow down and breathe deeply into your belly. Pressing your fingers into the sore spot while you bend forward helps too. Exhaling as your opposite foot lands can speed things along. Most stitches ease within a minute or two.