"Even without blood thinners, a severe cough can trigger a life-threatening abdominal bleed, prompting a call for heightened clinical vigilance."
This remarkable case of a 57-year-old Japanese man underscores a rare but potentially serious complication of forceful coughing: a rectus sheath hematoma (RSH). While typically associated with anticoagulant use or trauma, this patient’s RSH developed solely from persistent pneumonia-induced coughing, challenging conventional understanding and emphasizing the need for broader diagnostic considerations in cases of acute abdominal pain, particularly when accompanied by severe respiratory distress. The incident, detailed in the JMA Journal, serves as a critical reminder that seemingly benign symptoms can, in unusual circumstances, escalate to medical emergencies requiring immediate intervention.
The case of the 57-year-old Japanese man, who presented with a severe rectus sheath hematoma (RSH) following a week of intense coughing due to pneumonia, offers a stark illustration of an uncommon but potentially critical medical event. While RSH is often linked to the use of anticoagulant or antiplatelet medications, trauma, or significant abdominal strain, this individual’s case presented without these typical risk factors. His experience, documented by researchers from the Department of Respiratory Medicine at Kanazawa University Graduate School of Medical Sciences, including Kazuhiko Iwasaki, Satoshi Watanabe, and Seiji Yano, highlights the complex interplay between forceful bodily actions and vascular integrity, even in the absence of predisposing conditions.
The patient, a former smoker with a history of high blood pressure, was being treated for bronchopneumonia, identified through sputum culture as caused by Haemophilus influenzae. His week-long battle with relentless coughing escalated into a new, alarming symptom: a sharp pain on the right side of his abdomen. This discomfort rapidly progressed, accompanied by a spreading bruise across his abdominal wall. Subsequent imaging revealed significant internal bleeding within one of his abdominal muscles, specifically the rectus abdominis, commonly known as the "six-pack" muscle. The situation took a critical turn as the patient’s heart rate accelerated, and his circulatory system became unstable, necessitating urgent medical intervention.
The diagnosis of rectus sheath hematoma, defined as bleeding within the rectus abdominis muscle sheath, was established. However, what set this case apart, as detailed in the February 2026 publication in the JMA Journal, was the absence of common precipitating factors. The man was not on any blood-thinning medications (anticoagulants or antiplatelets), his blood clotting mechanisms were functioning normally, and he had no prior history of abdominal surgery. These negative findings made his case particularly intriguing and prompted a deeper investigation into the potential mechanisms driving such a severe internal bleed.
The patient’s medical history revealed he was a former smoker and had hypertension, both established cardiovascular risk factors. The bronchopneumonia was confirmed by a CT scan. The initial onset of abdominal pain, localized to the right side, began after approximately a week of persistent coughing. This discomfort acutely worsened two days prior to his admission to the hospital. Medical professionals observed significant discoloration extending from his lower abdomen to his right flank, along with a palpable, firm mass. A positive Carnett sign – where abdominal pain intensifies or remains unchanged when the patient tenses their abdominal muscles – strongly suggested the source of pain was within the abdominal wall itself, rather than originating from deeper abdominal organs. Crucially, all his clotting tests were within normal parameters, with no indication of underlying bleeding disorders, liver dysfunction, or connective tissue diseases.
Diagnostic imaging, specifically a CT scan, revealed multiple sites of bleeding within the right rectus abdominis muscle. The two largest hematomas contained approximately 18 milliliters and 15 milliliters of blood, respectively. Initially, the medical team opted for conservative management, closely monitoring the patient’s condition. However, his symptoms deteriorated. The abdominal pain intensified, and he developed tachycardia (a rapid heart rate) coupled with hemodynamically unstable vital signs. This rapid decline necessitated his transfer to a larger medical facility equipped to handle more complex cases.
At the tertiary care hospital, a contrast-enhanced CT scan provided a more detailed view of the abdominal musculature. This imaging confirmed the likely enlargement of the intramuscular hematomas, with the bleeding extending throughout the entire right rectus abdominis muscle. The superficial bruising on his skin had also continued to spread, reflecting the extent of the internal hemorrhage. Surgical intervention became imperative. Surgeons performed an exploratory laparotomy, accessing the rectus sheath. They meticulously removed multiple dark-red blood clots, thoroughly irrigated the affected area, and successfully controlled the bleeding. Due to the diffuse nature of the hematomas, a single bleeding artery could not be definitively identified as the sole culprit.
Following surgery, the patient spent two days in the intensive care unit. He required high-flow oxygen support but fortunately did not need mechanical ventilation. His surgical wound was managed with negative-pressure wound therapy, followed by a skin graft. After approximately a month of hospitalization and recovery, he was discharged in good overall condition.
Rectus sheath hematoma, while a recognized medical entity, is considered uncommon, accounting for an estimated 1% to 2% of all acute abdominal pain presentations, according to StatPearls, a clinical reference resource from the National Library of Medicine. A 2016 review cited within StatPearls indicated that RSH is more prevalent in women than men, with an average patient age of 67 years. Alarmingly, over 70% of individuals diagnosed with RSH are found to be taking anticoagulant medications, and many also report a history of trauma or significant physical exertion affecting the abdomen.
The primary blood vessels implicated in RSH are typically the superior or inferior epigastric arteries, which run parallel to the rectus abdominis muscle. The anatomy of the abdominal wall plays a crucial role; below the arcuate line, the posterior sheath of the rectus muscle is absent, rendering the inferior epigastric artery more susceptible to injury. Forceful muscle contractions, such as those experienced during strenuous exercise or intense coughing fits, are well-established triggers, particularly in individuals whose blood-thinning medications compromise their clotting ability.
In most instances, rectus sheath hematomas can be managed conservatively without surgical intervention. The overall mortality rate associated with RSH is reported to be below 2%, as per StatPearls. For patients experiencing persistent bleeding or hemodynamic instability, less invasive procedures like embolization, where a catheter is used to block the bleeding artery, are often employed. Open surgery is generally reserved for more severe or refractory cases. The authors of the Japanese case study noted that mortality rates can escalate significantly, potentially reaching up to 30%, in high-risk patient populations.
The unique circumstances of this 57-year-old man’s RSH were precisely what drew the attention of the researchers. His lack of typical risk factors, combined with the rapid progression of bleeding that necessitated surgical intervention, made his case a notable outlier. Previous reports of cough-induced RSH have often been less severe. For instance, a 2025 report in the Annals of Medicine and Surgery described a healthy 47-year-old man who developed a cough-induced hematoma that resolved with conservative measures including rest, pain management, and cough suppression, allowing for discharge within three days.
Another relevant report, published in July 2026 in the Journal of Surgical Case Reports, detailed the case of a 68-year-old man who was taking aspirin but not stronger anticoagulants. After experiencing a week of coughing due to an upper respiratory infection, he developed active bleeding from his superior epigastric artery, ultimately requiring surgical treatment. The authors of that study emphasized that forceful coughing can generate significant shearing forces capable of rupturing weakened epigastric vessels or tearing muscle fibers within the rectus abdominis.
The findings from the Japanese team carry significant implications for clinicians. Their message is a clear call to action: "Cough-induced RSH, although rare, can progress rapidly to hemodynamic instability." They urge healthcare providers to maintain a high index of suspicion for this condition in patients presenting with acute abdominal pain, accompanying abdominal wall discoloration, and a history of severe coughing, even in the absence of anticoagulant therapy.
For the vast majority of individuals, a severe cough, while uncomfortable, will not lead to such a serious internal injury. Acute coughs typically resolve within two to three weeks without significant complications. However, the appearance of sudden, severe abdominal pain during a coughing illness, particularly when accompanied by a visible bruise or a palpable lump in the abdominal wall, should be considered a signal to seek prompt medical evaluation. Furthermore, any signs of circulatory compromise, such as a racing heart, dizziness, or fainting, warrant immediate emergency medical attention.
Key Questions Answered
What is a rectus sheath hematoma?
A rectus sheath hematoma (RSH) is a collection of blood that forms within the rectus abdominis muscle, the long, paired muscles that run vertically along the front of the abdomen. This bleeding typically occurs due to damage to the superior or inferior epigastric arteries, which supply blood to this muscle.
What happened to this patient?
A 57-year-old man in Japan developed a severe RSH after experiencing a week of intense coughing due to pneumonia. The condition manifested as right-sided abdominal pain, a spreading bruise, and internal bleeding within his abdominal muscle, ultimately requiring emergency surgical intervention to control the hemorrhage.
Why was his case unusual?
This patient’s case was unusual because he had none of the common risk factors typically associated with RSH. He was not taking any anticoagulant or antiplatelet medications, his blood clotting function was normal, and he had no prior history of abdominal surgery. This absence of typical precipitating factors made his rapid development of a significant hematoma particularly noteworthy.
How is the condition usually treated?
Most cases of rectus sheath hematoma are managed non-surgically with rest, pain relief, and, if applicable, reversal of anticoagulant therapy. For patients experiencing persistent bleeding or hemodynamic instability, less invasive procedures like arterial embolization are often considered. Open surgery is typically reserved for severe or complicated cases where conservative measures and embolization are insufficient.
How common is it?
Rectus sheath hematoma is considered an uncommon cause of acute abdominal pain. Estimates suggest it accounts for approximately 1% to 2% of all cases of acute abdominal pain.
When should someone with a cough seek care for belly pain?
Individuals experiencing sudden, severe abdominal pain, especially when accompanied by a bruise or a firm lump on the abdomen, during a coughing illness should seek prompt medical attention. Additionally, if a cough is associated with a racing heart, dizziness, or a feeling of faintness, immediate emergency care is warranted.
