Side stitch: why it happens and how to avoid it

If you do sport, you’re more than likely familiar with the sharp pain in your side. What causes a stitch? And how do you prevent or get rid of it?

Text: Abital Rauber; photo: iStock/Alvarez

What is a side stitch?

A side stitch is a pain that mainly occurs during physical exertion, often in connection with running or other endurance sports. You will feel an intense stabbing pain either on the left side at the level of the spleen or on the right side by the liver. Sometimes the pain is even felt on both sides. Anyone can be affected. It doesn’t matter whether you’re an amateur or professional runner, a cyclist, swimmer or rower. A side stitch is unpleasant, but it’s not dangerous. It doesn’t harm the body or indicate serious health problems.

“Experts agree that side stitches are related to breathing.”
Ramon Gubser, manager of the Physiozentrum physiotherapy centre in Uster

What causes a side stitch?

Scientists still aren’t 100% sure what causes a side stitch. This is primarily due to the fact that the pain disappears as quickly as it starts, which makes examinations difficult. “But experts do agree that it has something to do with breathing,” says Ramon Gubser, manager of the Physiozentrum physiotherapy centre in Uster. Many experts believe that the pain is triggered by the diaphragm. And there are also links to blood circulation and the supply of oxygen to the organs.

The diaphragm as a trigger for side stitch

The diaphragm is in the middle of the upper body and separates the lungs from the abdominal area. It lifts and lowers with each breath. The theory is that if you don’t breathe correctly or evenly when you’re running, this creates asymmetry and thus the side pain, triggered by a cramping of the diaphragm and its attached structures.

Blood flow to the organs as a cause

“The blood supply to the organs is restricted while exercising, because the muscles need more blood,” explains Gubser. Studies have shown that blood flow to the liver and spleen decreases significantly during physical exertion. Ultrasound images also show the deformation of the spleen and the capsule of the liver due to the strain. As both are very sensitive to pain, they may be responsible for the side stitch.

How can you prevent a side stitch while jogging?

The fact that a stitch often occurs when you go jogging directly after eating fits with the theory of blood redistribution. “The gastrointestinal tract needs blood to digest food, which muscles also need for sport,” explains Gubser. Running on a full stomach leads to problems with the distribution of blood flow in the body. If you want to avoid getting a stitch, Gubser recommends not eating a big meal two to three hours before exercising.

If you’re hungry, small and easily digestible snacks such as bananas can help. It’s important to find a balance: your stomach shouldn’t be too full or too empty.

“If you want to avoid getting a stitch, you shouldn’t eat a big meal two to three hours before exercising.”
Ramon Gubser, manager of the Physiozentrum physiotherapy centre in Uster

Another tip to prevent side stitch is to start training slowly and build the intensity gradually. This allows the body to slowly adapt the blood flow to its needs. Consistent training also protects against side stitch because it strengthens the entire system – i.e. muscle functions and blood circulation through the body.

Some experts also recommend breathing exercises or core training to prevent side stitch. Core training aims to strengthen the middle of the body – especially the area between the diaphragm and hips. However, the effectiveness of these measures has not been scientifically proven.

What helps against a side stitch?

A side stitch is harmless, but can be very unpleasant. The pain often forces the runner to slow their pace immediately or even break off their training. There’s no miracle one-size-fits-all cure against the pain. You have to find out what helps you. Some people say that it helps to breathe evenly and deeply into the stomach, while others prefer to take a short break and stretch their sides and flanks.

Right or left side stitch without exertion

In rare cases, a side stitch can occur without physical exertion. There are a number of reasons for this:

Right side stitch without exertion

If a side stitch occurs on the right side without exertion, this may be due to the liver. It is located to the top right of the abdomen and is attached to the diaphragm by several ligaments.

Left side stitch without exertion

A circulatory disorder of the spleen may be responsible for the occurrence of side stitches on the left side at rest. If you have frequent or prolonged side stitches when you are at rest – on the left or right side – you should see a doctor.

Bent posture

Side stitches can occur if you remain in a bent posture for a long time. Pressure builds up in the stomach, for example during long car journeys or air travel.

During pregnancy

Side stitches during pregnancy are largely normal – especially when your belly gets bigger. This is due to the baby growing and taking up more space. The baby also needs blood and oxygen, which affects the blood supply to the other organs. However, a side stitch can also occur while walking or strolling. “Side stitches are triggered more easily during pregnancy,” says Gubser. In addition, women are often still quite active in the early stages of pregnancy. Later on, expectant mums tend to move less, so the lack of movement also causes side stitches more quickly.

About the expert

Ramon Gubser is a physiotherapist at the Physiozentrum group practice, which has locations throughout Switzerland. He manages the Uster branch. Gubser specialises in manual therapy and vertigo therapy.

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