The diaphragm is a dome-shaped muscle located at the base of the chest, separating the thoracic cavity, which houses the lungs and heart, from the abdominal cavity below. It contracts and flattens during inhalation, creating space for the lungs to expand and draw in air. When exhaling, the diaphragm relaxes and curves upward, pushing air out of the lungs. Pain in this region often stems from a variety of causes, ranging from muscular issues to more complex underlying conditions.
Diaphragm Muscle Strain and Injury
Direct physical stress on the diaphragm and surrounding muscles can lead to pain. Strenuous activities, such as intense coughing, forceful sneezing, heavy lifting, or vigorous exercise, can overstretch or tear the diaphragm muscle fibers. This can manifest as a sharp or tight pain, sometimes described as a “side stitch,” particularly during physical exertion. Such pain often restricts the ability to take a full, deep breath without discomfort.
The intercostal muscles, situated between the ribs, also play a role in breathing and can be strained or injured. These muscles help expand and contract the chest cavity, and their strain can cause localized pain and tenderness in the ribs. Injuries from direct trauma to the chest or abdomen, like those sustained in a car accident or a fall, can also result in strain or even a tear of the diaphragm itself, leading to intermittent or persistent pain.
Pain Originating from Abdominal Issues
Pain felt in the diaphragm area can be referred from issues within the abdominal cavity. One common cause is gastroesophageal reflux disease (GERD), where stomach acid flows back into the esophagus, causing a burning sensation in the chest that can extend to the diaphragm region. This acid irritation can lead to discomfort and sometimes shortness of breath.
Conditions affecting organs like the gallbladder, liver, or spleen can also cause referred pain in the diaphragm area due to shared nerve pathways. For instance, gallstones or inflammation of the gallbladder may lead to pain felt in the right shoulder or upper right abdomen, which can extend towards the diaphragm. Problems with the liver, such as inflammation or enlargement, can cause discomfort that radiates to the diaphragm. A ruptured or enlarged spleen, located in the upper left abdomen, can irritate the left side of the diaphragm, often resulting in pain referred to the left shoulder, a phenomenon known as Kehr’s sign.
Pain Originating from Thoracic Issues
Conditions within the chest cavity can also cause pain that is perceived in or around the diaphragm. Pleurisy, an inflammation of the pleura, the thin lining surrounding the lungs and chest wall, causes sharp chest pain when these layers rub against each other. This pain worsens with deep breaths, coughing, or sneezing, and can spread to the shoulder or back.
Pneumonia, an infection causing inflammation of the lung air sacs, presents with chest pain that can be sharp and worsen with breathing or coughing. This discomfort can be felt in the diaphragm region due to the proximity of the lungs and the inflammatory process. Heart conditions, such as pericarditis, which is inflammation of the sac surrounding the heart, can also cause chest pain that may radiate to the neck, shoulders, or abdomen, sometimes mimicking diaphragm pain. The pain from pericarditis often feels better when sitting up and leaning forward, and worse when lying down or taking a deep breath.
Other Direct Diaphragm-Related Conditions
Some conditions directly affect the diaphragm’s structure, function, or nerve supply. A hiatal hernia occurs when a portion of the stomach pushes upward through an opening in the diaphragm into the chest cavity. This can lead to symptoms like heartburn, acid reflux, and chest pain.
Irritation or damage to the phrenic nerve, which controls the diaphragm’s movement, can also be a source of pain. Damage to this nerve, from trauma, surgery, or underlying medical conditions, can lead to diaphragm weakness or paralysis, causing difficulty breathing and sometimes shoulder pain. Tumors can develop in or on the diaphragm, leading to symptoms such as coughing, pain, and difficulty breathing. Their presence can directly impact diaphragmatic function and cause localized discomfort.