Diaphragm pain arises from a surprisingly wide range of causes, from simple muscle strain after a hard workout to serious conditions like traumatic rupture, infection, or even endometriosis. Because the diaphragm sits at the border between the chest and abdomen and is wired into a nerve pathway that can send pain signals to the shoulder, neck, and upper belly, identifying where the pain actually originates can be tricky. The causes range from benign and self-limiting to urgent, and understanding the possibilities helps you recognize when discomfort around your diaphragm deserves medical attention.
Muscle Strain and Overuse
The diaphragm is a dome-shaped muscle, and like any muscle, it can be strained. Heavy coughing, intense exercise, forceful sneezing, or even prolonged laughing can overwork it and produce aching or sharp pain in the lower chest or upper abdomen. This is probably the most common reason people notice diaphragm-area pain, and it usually resolves on its own with rest. The sensation tends to worsen with deep breathing, coughing, or twisting motions, which makes sense because every one of those actions forces the diaphragm to contract.
A less obvious trigger is heavy lifting or straining, which raises intra-abdominal pressure and makes the diaphragm work harder. People recovering from a respiratory illness involving persistent coughing sometimes develop lingering soreness in the diaphragm region that can be mistaken for a rib or lung problem. If the pain is mild, worsens with specific movements, and eases with rest, muscular strain is the likely culprit. Persistent or severe cases, however, warrant imaging to rule out structural damage.
Trauma and Diaphragmatic Rupture
Blunt force to the lower chest or upper abdomen can tear the diaphragm outright. Car accidents, falls from height, and crush injuries are the most common causes of blunt diaphragm injuries. The mechanism involves a sudden spike in intra-abdominal pressure that overwhelms the diaphragm’s tensile strength. Under normal conditions, the pressure difference between the abdominal and chest cavities sits around 7 to 20 centimeters of water pressure. In a high-speed collision or a serious fall, that gradient can exceed 100 centimeters of water pressure, which is enough to rip the muscle.1PubMed Central. Post-traumatic diaphragmatic rupture with pericardial denudation: A case report
Diaphragmatic rupture is often missed initially because the symptoms overlap with other chest and abdominal injuries. Pain may be severe and located in the lower chest or flank, and breathing may feel labored. Left-sided tears are more common than right-sided ones because the liver offers some structural reinforcement on the right. If not repaired, a torn diaphragm can allow abdominal organs to migrate into the chest cavity over time, creating a traumatic hernia that compresses the lung and produces worsening symptoms weeks or even months after the original injury.
Hiatal Hernia and Gastrointestinal Problems
The diaphragm has a natural opening called the esophageal hiatus where the esophagus passes through to reach the stomach. When part of the stomach pushes upward through that opening, it creates a hiatal hernia. Small hiatal hernias are extremely common and often cause no symptoms at all. Larger ones, though, can produce chest pain, upper abdominal pain, nausea, and vomiting, particularly in people who already have acid reflux. In rare extreme cases, a giant hiatal hernia can pull other organs into the chest cavity alongside the stomach. One reported case involved an 84-year-old woman whose hernia was large enough to contain portions of the pancreas, small bowel, and colon, and she presented with chest and abdominal pain along with nausea.2Cureus. Breaking Boundaries: A Case Report of Giant Hiatal Hernia Housing Pancreas, Stomach, Small Bowel, and Colon
Beyond hernias, any inflammation in the organs directly beneath the diaphragm can produce pain that feels like it is coming from the diaphragm itself. Liver inflammation, gallbladder disease, splenic enlargement, and pancreatitis can all irritate the undersurface of the diaphragm and produce referred pain in the chest or shoulder. The diaphragm’s position as a boundary between two body compartments means it often takes the blame for problems originating elsewhere.
The Phrenic Nerve and Referred Pain
One of the most counterintuitive things about diaphragm pain is where you feel it. The diaphragm is supplied by the phrenic nerve, which originates from the third through fifth cervical spinal segments in the neck. The phrenic nerve carries sensory information from the diaphragm, the undersurface of the peritoneum over the liver and spleen, the pericardium around the heart, and the lower portions of the pleural lining around the lungs.3European Respiratory Journal. Referred shoulder pain (C4 dermatome) can adversely impact diaphragm pacing with intramuscular electrodes When any of these structures are irritated, the brain can misinterpret the signal as pain coming from the neck or shoulder instead, a phenomenon known as Kehr’s sign.
This means someone with a ruptured spleen, a liver abscess, or even free air under the diaphragm after surgery might experience shoulder-tip pain rather than abdominal pain. It also means diaphragm pain itself may present as shoulder or neck discomfort. If you develop unexplained shoulder pain alongside breathing difficulty, abdominal symptoms, or after a recent medical procedure, the diaphragm and its surrounding structures are worth considering as the actual source.
Pain After Surgery
Shoulder and upper abdominal pain after laparoscopic surgery is so common it has its own body of research. During laparoscopic procedures, carbon dioxide gas is pumped into the abdomen to create a working space for the surgeon. This inflates the abdomen, stretches the diaphragm under pressure, and irritates the phrenic nerve. The result is pain referred to the shoulder that can persist for a day or more after the procedure.4PubMed Central. Postoperative Shoulder Pain after Laparoscopic Surgery The exact mechanism is still debated, but the leading explanation centers on diaphragmatic overstretching combined with chemical irritation from the residual gas.
Post-surgical diaphragm pain is distinct from surgical wound pain and can catch patients off guard. Moving around, which helps the residual gas dissipate, tends to provide faster relief than lying still. In some cases, pain-management strategies target the phrenic nerve pathway specifically. For people who have had any abdominal or lower chest surgery, diaphragm-area discomfort during recovery is common and usually resolves within a few days, though persistent or worsening pain always warrants a call to the surgical team.
Subphrenic Infections and Abscesses
An abscess forming just below the diaphragm, in the space between the diaphragm and the liver or spleen, can produce severe pain in the lower chest and upper abdomen. These subphrenic abscesses most commonly develop after abdominal surgery, with roughly 70 percent occurring in the postoperative period. They can also follow a perforated organ, a ruptured appendix, or complicated diverticulitis. Mortality from intra-abdominal abscesses can be high if they are not drained promptly.5PubMed Central. Minimally invasive video-assisted trans-diaphragmatic drainage of a subphrenic complicated abscess
Symptoms typically include fever, pain that worsens with breathing, and sometimes referred shoulder pain via the phrenic nerve pathway. Because the abscess sits against the underside of the diaphragm, every breath moves inflamed tissue, making deep inspiration particularly painful. Imaging with CT scan is the standard way to identify these collections, and treatment usually involves drainage, either through a catheter placed through the skin or, less commonly, through surgical intervention.
Diaphragmatic Endometriosis
Endometriosis, a condition in which tissue similar to the uterine lining grows outside the uterus, can involve the diaphragm. This is a rare but underrecognized cause of cyclical chest and diaphragm-area pain in women. The most dramatic presentation is catamenial pneumothorax, a collapsed lung that occurs around the time of menstruation. In one reported case, a 31-year-old woman experienced repeated episodes of pneumothorax. Surgery revealed that endometrial implants had created numerous holes in her diaphragm.6PubMed Central. Diaphragmatic Endometriosis Presenting as Recurrent Catamenial Pneumothorax: A Case Report
In another case, a 40-year-old woman with two episodes of right-sided pneumothorax timed to her menstrual cycle underwent thoracoscopy that found brownish spots on the right diaphragm. Tissue analysis confirmed endometrial stromal cells had infiltrated the diaphragmatic muscle.7PubMed. Catamenial pneumothorax caused by diaphragmatic stromal endometriosis The right diaphragm is affected more often than the left, and symptoms can include right shoulder pain, chest tightness, and shortness of breath that worsens predictably around menstruation. If you notice a cyclical pattern to chest or diaphragm pain that aligns with your period, bringing up the possibility of diaphragmatic endometriosis with your doctor is worth the conversation, especially if you have a history of pelvic endometriosis.
Diaphragmatic Myoclonus
Sometimes the diaphragm develops involuntary, rhythmic contractions, a condition called diaphragmatic myoclonus. These are rapid, repetitive spasms that can feel like a fluttering or thumping sensation in the chest or abdomen and may produce discomfort or pain. The exact cause is not fully understood, but involuntary muscle movement in the diaphragm can result from abnormal excitation within the central or peripheral nervous system, or from direct irritation of the phrenic nerve or the diaphragm itself.8Heart Rhythm. Atrioventricular dyssynchrony provoked diaphragmatic myoclonus
In some cases, cardiac rhythm disturbances can provoke diaphragmatic myoclonus, which creates a confusing clinical picture where chest discomfort seems to be cardiac but is actually muscular. The spasms can also follow nerve damage, certain medications, metabolic disturbances, or brain lesions. Diaphragmatic myoclonus is not the same as ordinary hiccups, though the two are related in that both involve involuntary diaphragm contractions. Persistent rhythmic spasms that do not respond to typical hiccup remedies and are associated with pain or breathing difficulty deserve evaluation by a neurologist or pulmonologist.
Autoimmune Conditions Affecting the Diaphragm
The diaphragm is skeletal muscle, which means it can be targeted by inflammatory muscle diseases. Polymyositis, an autoimmune condition that causes inflammation and weakness in muscles throughout the body, usually affects the shoulders, hips, and neck. But it can also involve the diaphragm, weakening it to the point where breathing becomes difficult. In severe cases, diaphragmatic involvement can trigger acute respiratory failure.9PubMed Central. Polymyositis: A Rare Cause of Acute Respiratory Failure and a Diagnostic Dilemma
Related conditions like dermatomyositis and some overlap syndromes can produce similar effects. The pain from autoimmune diaphragm involvement tends to be more diffuse than the sharp localized pain you would get from a strain or rupture, and it is usually accompanied by generalized muscle weakness elsewhere. Difficulty lying flat or worsening breathlessness over weeks should raise suspicion, especially in someone already diagnosed with or being evaluated for an inflammatory myopathy.
Cardiac Events That Mimic Diaphragm Pain
Heart attacks do not always announce themselves with classic crushing chest pain. In some people, particularly those with diabetes, the predominant symptom is abdominal pain that can feel like it is coming from the diaphragm area. One documented case involved a 60-year-old man with diabetes and prior heart disease who presented with syncope and severe abdominal pain but no chest pain at all. His electrocardiogram revealed an active heart attack affecting the inferior wall of the heart, and angiography found a blocked right coronary artery.10PubMed Central. Atypical Presentation of Acute Myocardial Infarction As Syncope and Abdominal Pain in the Absence of Chest Pain or Discomfort
The inferior wall of the heart rests directly on top of the diaphragm, so blockages in the artery supplying that region can produce pain that radiates downward into the upper abdomen rather than the classic pattern of pressure radiating to the left arm and jaw. Anyone with risk factors for heart disease, including diabetes, high blood pressure, and prior cardiac events, should treat new or unexplained upper abdominal or diaphragm-area pain as potentially cardiac until proven otherwise.
Panic Disorder and Chest Pain
About a quarter of patients who see a doctor for chest pain turn out to have panic disorder rather than a cardiac or structural problem.11PubMed Central. Panic Disorder and Chest Pain: Mechanisms, Morbidity, and Management Panic attacks can produce chest tightness, shortness of breath, and pain in the diaphragm area through multiple pathways, including hyperventilation, esophageal spasm, and increased muscle tension. The diaphragm itself can cramp during hyperventilation because rapid, shallow breathing disrupts its normal rhythmic contraction.
This does not mean the pain is “not real.” The discomfort is genuine and can be severe enough to send someone to an emergency room convinced they are having a heart attack. The key distinguishing features are the episodic nature, association with anxiety or stressful situations, and the absence of findings on cardiac testing. Recognizing panic disorder as a cause of diaphragm-area pain matters because it changes the treatment path entirely, from cardiology to mental health support and sometimes medication.
Tumors of the Diaphragm
Primary tumors originating in the diaphragm are rare. In one study of 18 patients with primary diaphragm tumors, 14 had no symptoms at all before their tumors were found incidentally during surgery or imaging for other reasons. Only two patients reported chest pain, and their tumors were small, measuring under 2 centimeters. A single patient with a larger tumor of about 7 centimeters reported a foreign body sensation in the upper abdomen.12PubMed Central. Analysis of clinicopathological features of primary diaphragm tumors: A single‐center study
More commonly, cancer reaches the diaphragm through spread from nearby organs, particularly the lungs, liver, and stomach. Metastatic involvement of the diaphragm can produce pain, breathing difficulty, and referred shoulder discomfort. Because primary diaphragm tumors are so uncommon and often silent, pain in the diaphragm area is far more likely to have one of the other causes discussed here. Still, persistent unexplained pain in the lower chest or upper abdomen, especially alongside weight loss or other systemic symptoms, warrants imaging.
Congenital Diaphragmatic Defects in Adults
Congenital diaphragmatic hernias, openings in the diaphragm present from birth, are usually diagnosed in infancy because they cause obvious breathing problems. Occasionally, though, a smaller defect goes undetected for decades and only becomes symptomatic in adulthood. A Bochdalek hernia is the most common type, typically located on the left posterior side of the diaphragm. In one case, an adult presented with intermittent pain in the left upper abdomen and lower chest. Imaging revealed a complicated left diaphragmatic hernia containing stomach and abdominal fat with signs of inflammation and early tissue damage from impaired blood flow.13Respiratory Medicine Case Reports. Late presentation of a congenital problem; complicated left-sided Bochdalek’s hernia in an adult: A case report
Adults with previously undiagnosed congenital diaphragmatic defects may experience vague intermittent symptoms for years before a complication such as organ incarceration or ischemia brings the condition to light. The symptoms mimic many other conditions, including gastric reflux, musculoskeletal chest pain, or even cardiac disease. Diagnosis typically comes from CT scanning, and repair usually requires surgery.
How Diaphragm Problems Are Evaluated
Diaphragmatic dysfunction is commonly underdiagnosed because its presentation overlaps with so many other conditions. Shortness of breath, chest pain, upper abdominal pain, and shoulder discomfort are all nonspecific symptoms that point in dozens of directions before the diaphragm comes to mind. Ultrasound has become an increasingly valued tool for evaluating diaphragm function because it is noninvasive, does not involve radiation, produces immediate results, and can be performed at the bedside.14PubMed Central. Diaphragmatic ultrasound: a review of its methodological aspects and clinical uses It can measure diaphragm thickness, excursion during breathing, and changes that suggest weakness or paralysis.
CT scanning remains the gold standard for identifying structural problems such as hernias, ruptures, abscesses, and tumors. MRI is sometimes used when soft tissue detail matters, particularly in cases where endometriosis or a mass is suspected. Fluoroscopy, which captures the diaphragm in real-time motion, can reveal paradoxical movement where one side of the diaphragm rises when it should be falling, a hallmark of phrenic nerve dysfunction. Nerve conduction studies of the phrenic nerve round out the diagnostic toolkit when neuromuscular causes are suspected. The challenge is usually not the imaging itself but knowing when to look at the diaphragm in the first place, since so many of its symptoms get attributed to other structures sharing the same neighborhood.