The symptoms of intercostal muscle strain may vary slightly, depending on how the injury occurred, and may include:
- Sudden, severe upper back/rib pain. Upper back pain or pain in the rib cage may be significant and come on suddenly, especially if the injury was caused by sudden impact or a blow to the chest or back. Additionally, a sudden increase in physical activity can strain an intercostal muscle and lead to sudden, intense pain.
- Gradually worsening pain. Upper back pain may develop progressively over several days or weeks if repetitive, gradual stress is placed on the intercostal muscles. This type of muscle strain is most common after participating in sports such as rowing, swimming, or softball/baseball.
- Muscle tension and stiffness. Muscles may react to an injury by tensing up, causing upper back pain and stiffness with everyday movements such as bending or twisting the upper body. Tension in the intercostal muscles may also lead to muscle spasms, increasing pain.
- Difficulty breathing. Taking a full breath may be too painful with an intercostal muscle strain, causing breathing to become shallow. Breathing in shorter, shallower breaths to avoid pain can ultimately lead to less oxygen traveling through the body, undermining the healing process. More severe complications from intercostal muscle strain are rare.
- Tenderness. The affected muscles and adjacent ribs may be sensitive to the touch. Additionally, wearing tight clothing or carrying a backpack or purse over the strained muscles can worsen pain.
- Local inflammation. The strained intercostal muscles may swell, increasing sensitivity in the affected area. In rare cases, this swelling can cause blood to pool or clot around the strained muscles, called a hematoma.
Injuring the intercostal muscles can potentially lead to further complications. While rare, such complications may include irritating an intercostal nerve or complications due to shallow breathing.
Diagnosing Intercostal Muscle Strain
Only a qualified health professional can accurately diagnose an intercostal muscle strain. The diagnostic process for intercostal strain typically includes:
- A collected medical history, including a review of current symptoms and information on when and how the pain started. A medical history may also include information on sleep habits, physical activity and exercise habits, or any recent injuries to the torso.
- A physical exam, in which the doctor will feel the painful area by hand (called palpation) to check for tenderness and swelling. A physical exam may involve bending or twisting the torso to test how movement and postures affect pain. Additionally, a doctor may use a stethoscope to listen for signs of shallow breathing.
A diagnostic imaging test (such as an x-ray or MRI scan) is typically not needed to diagnose an intercostal muscle strain. In some cases, an imaging test may be ordered to rule out the possibility of internal injury, such as a fractured rib or bruised lung.