2. Muscle Strain
One of the most common reasons that a person will experience pain in the side of their chest is from a muscle strain. Trauma to the area or simple overuse can cause a person to experience pain in a certain area of the chest. A muscle strain may occur from participating in an intense upper body activity. Some sports that require upper body strength can cause a person to experience muscle strain.
Overexertion of the muscles through a vigorous activity such as chopping wood, painting a ceiling, or anything that involves intense upper body movement, can cause pain in the chest muscles. A person may also experience muscle pain as a result of anxiety or tension in the area. Most of the time taking an over the counter pain medication and simply getting some rest so your muscles can heal, will be enough to ease the symptoms caused by a muscle strain.