A 57-year-old man in Japan had been coughing hard for a week from pneumonia when a new pain appeared on the right side of his belly. A bruise spread across his abdomen, and scans showed pools of blood inside one of his abdominal muscles. While doctors monitored him, his heart began racing, and his circulation became unstable.
The diagnosis was a rectus sheath hematoma, bleeding within the long "six-pack" muscle that runs down the front of the abdomen. What made the case, published in February 2026 in JMA Journal, stand out is what the man did not have. He was not taking blood thinners or antiplatelet drugs, his clotting was normal, and he had never had surgery.
From Pneumonia Cough to a Spreading Bruise
The patient was described by Kazuhiko Iwasaki, Satoshi Watanabe and Seiji Yano of the Department of Respiratory Medicine at Kanazawa University Graduate School of Medical Sciences. He had high blood pressure and was a former smoker. A sputum culture grew Haemophilus influenzae, a bacterium that commonly causes respiratory infections, and a CT scan confirmed bronchopneumonia.
After a week of persistent coughing, he developed discomfort on the right side of his abdomen that suddenly worsened two days before he was admitted. Doctors found discoloration spreading from his lower abdomen to his right flank and a firm, poorly defined mass. He also had a positive Carnett sign, meaning the pain stayed the same or worsened when he tensed his stomach muscles, a clue that the problem lay in the abdominal wall rather than in deeper organs.
His clotting tests were normal, with "no evidence of bleeding disorders, liver failure, or connective tissue disease," the authors wrote.
Two Blood Pools, Then a Turn for the Worse
The CT scan found multiple bleeds inside the right rectus abdominis muscle. The two largest held about 18 milliliters and 15 milliliters of blood.
Doctors initially kept him under observation. But "during observation, the patient's abdominal pain worsened, and he developed tachycardia with unstable hemodynamics," the authors wrote, so he was transferred to a larger hospital. There, a contrast CT showed "possible enlargement of the intramuscular hematomas with extension throughout the right rectus abdominis muscle," and the bruising on his skin had spread.
Surgeons opened the sheath covering the muscle, removed multiple dark-red clots, washed out the area and stopped the bleeding. Because there were several hematomas, they could not pinpoint a single artery responsible. He spent two days in intensive care and needed high-flow oxygen but not a breathing tube. His wound was treated with negative-pressure therapy and later a skin graft, and he was discharged in good condition after about a month.
Blood Thinners Are the Usual Culprit, Not Coughing Alone
Rectus sheath hematoma is uncommon. According to StatPearls, a clinical reference hosted by the National Library of Medicine, it accounts for about 1% to 2% of acute abdominal pain cases. In one 2016 review cited there, it was more common in women than men, and patients averaged 67 years old. StatPearls reports that more than 70% of patients are on anticoagulants and also experience trauma or significant force to the area.
The bleeding usually comes from the superior or inferior epigastric arteries, which run along the rectus muscle. Below a landmark called the arcuate line, the back of the muscle lacks a protective sheath, leaving the inferior epigastric artery especially vulnerable. Forceful muscle contractions during exercise or coughing are recognized triggers, particularly in people on blood thinners.
Most cases resolve without surgery, and overall mortality is below 2%, according to StatPearls. When bleeding and instability persist, doctors can often thread a catheter into the artery and block it, a procedure called embolization, and open surgery is only rarely required. The Japanese authors note that death rates can reach 30% in high-risk groups.
That is why the case caught its authors' attention. The man had none of the usual risk factors, yet his bleeding progressed quickly enough to require an operation. Other cough-related cases have been far milder. A 2025 report in Annals of Medicine and Surgery described a healthy 47-year-old man with a cough-induced hematoma who recovered with rest, pain relief, and cough suppression and went home on day 3.
A July 2026 report in the Journal of Surgical Case Reports described a 68-year-old man who was taking aspirin but no anticoagulants. After a week of coughing from an upper respiratory infection, he developed active bleeding from the superior epigastric artery and needed surgery. Those authors wrote that forceful coughing "can generate sufficient shearing stress to rupture weakened epigastric vessels or tear rectus muscle fibers."
Signs That a Cough Has Done More Than Irritate
The Japanese team's message is aimed at clinicians. "Cough-induced RSH, although rare, can progress rapidly to hemodynamic instability," they wrote, urging doctors to suspect it "in patients with acute abdominal pain, abdominal wall discoloration, and severe coughing, even in the absence of anticoagulant therapy."
For most people, even a bad cough will never cause this kind of injury. Most acute coughs clear up within two to three weeks. But sudden, severe abdominal pain during a coughing illness, especially with a bruise or firm lump on the belly, is a reason to seek prompt medical care. A racing heart, dizziness, or fainting calls for emergency attention.
Key Questions Answered
What is a rectus sheath hematoma?
It is bleeding inside the rectus abdominis, the long muscle down the front of the abdomen, usually from injury to the epigastric arteries.
What happened to this patient?
A 57-year-old man with pneumonia coughed severely for a week, then developed right-sided abdominal pain, a spreading bruise, and bleeding within his abdominal muscle that required urgent surgery.
Why was his case unusual?
Most people with this condition take blood thinners. He took no anticoagulant or antiplatelet drugs, had normal clotting, and had never had surgery.
How is the condition usually treated?
Most cases are managed with rest, pain relief, and reversal of blood thinners. Embolization or surgery is reserved for ongoing bleeding or unstable patients.
How common is it?
StatPearls estimates that it accounts for about 1% to 2% of acute abdominal pain cases.
When should someone with a cough seek care for belly pain?
Sudden, severe abdominal pain, a bruise or lump on the abdomen, a racing heart, or dizziness during a coughing illness warrant prompt medical attention.
Published by Medicaldaily.com
