An individual who has pain in the right side of their chest may have a muscle strain in that area. A muscle strain is also commonly referred to as a pulled muscle and occurs when an individual overstretches or tears tissue in a certain muscle. Muscle strain is a common occurrence in the chest because there are three vital muscles, called intercostal muscles, present in the upper trunk. The intercostal muscles stabilize an individual's upper body and help them breathe properly.
The most common cause of a muscle strain in the upper chest is from the overuse of the affected muscle. Reaching the arms above the head for extended periods, skipping warm-ups before physical activity, lifting while twisting the body, poor flexibility, and injury from malfunctioning equipment are all common causes of muscle strain in the chest. An individual who has a muscle strain in their upper torso that is causing right-sided chest pain may experience swelling, pain when breathing, bruising, and muscle spasms.