Conditions such as costochondritis, ruptured spleen and rib fractures may cause left side rib pain, according to Healthline. Other possible causes include osteoporosis and pleurisy.
Costochondritis, or Tietze’s syndrome, involves inflammation of the cartilage of the rib cage and is most common in women over 40, states Healthline. Symptoms include localized pain around the fourth, fifth and sixth ribs where they attach to the sternum. While the cause of costochondritis often goes undetermined, the condition may stem from trauma to the chest, physical strain or certain respiratory conditions. Other causes include arthritis or severe coughing.
In addition to pain in the left side of the abdomen under the rib cage, a ruptured spleen may cause symptoms such as blurred vision, confusion, fainting and signs of shock, notes WebMD. A ruptured spleen is a medical emergency as it causes internal bleeding. Spleen injuries often occur as a result of motor vehicle accidents, contact sport injuries, bicycle accidents and domestic violence.
Fractures are possible at any age and happen when the bone receives more pressure than it can sustain, states WebMD. While most rib fractures result from a blow to the chest area, ribs may also fracture from violent coughing. Osteoporosis, a condition which weakens the bones, makes fracturing more likely.