What causes muscle spasm under right rib cage?

Sometimes, the muscles under your right rib cage can spasm, which means they tighten up suddenly. This can happen when your body doesn't have enough of certain electrolytes—like calcium, magnesium, and potassium—that help your muscles work properly.

If you are very active or have overworked your muscles, they may get tired and start to spasm. Other times, a small strain or sudden movement may cause a muscle cramp. These spasms are generally not serious and tend to go away on their own after a short time.

Drinking plenty of water, having a balanced diet with fruits and vegetables, and doing gentle stretches can help prevent muscle spasms. However, if the spasm does not resolve, becomes very painful, or occurs frequently, you can use our free symptom checker to better understand what might be causing your discomfort and whether you should seek medical care.