Symptoms:
A sharp, temporary, pain in the side.

Cause:
This pain is caused by a spasm in the diaphragm, when this muscle between your chest and abdomen does not receive enough oxygen.

Running is a common immediate cause. The dual pressure from the contracted belly muscles (caused by the raised knee during running) and the expanded lungs from above (caused by deeper breathing) can momentarily shut off blood flow to the diaphragm. This causes it to cramp.

Not breathing evenly can cause you to get these cramps, even when heavily laughing.

However, the pain can also come from trapped gas in the intestines.

If the pain is only on the right side, it may be due to temporary lack of oxygen to the liver.

Treatment:
• Stop what you are doing, and let your muscles calm down. Exhale deeply, and take slow deep breaths in and out. You may wish to massage your side as you do this.

• Learn to breath from the diaphragm more, and less from the chest. This is part of the problem.

• Do not do very strenuous exercise closer than 2 hours to a meal.