Health condition
Superior mesenteric artery syndrome
SMA syndrome is a rare cause of upper gut obstruction in which the duodenum is compressed between two arteries, typically after rapid weight loss; nutrition restores the protective fat pad in most cases.
Why trust this guide
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Editorial team
Written by our editorial team from the UK sources listed on each page.
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Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
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Current for 2026
Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.
Key facts
The essentials at a glance.
The symptoms to recognise, when to seek help, which specialist to see, and what treatment usually involves.
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Typical symptoms: fullness, nausea, vomiting and pain after meals, often relieved by lying on the left side or knees-to-chest
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Classically follows rapid weight loss, from illness, surgery, or an eating disorder
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Diagnosis: CT scanning showing duodenal compression with a narrowed aorto-mesenteric angle
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Treatment is nutritional first, restoring weight via small meals or feeding tubes, with surgery (duodenojejunostomy) for refractory cases
Understanding the condition
What it is and what happens next.
What causes it, how it is diagnosed, and the treatment routes available in the UK.
What it is and how it feels
The third part of the duodenum passes through the angle between the aorta and the superior mesenteric artery, normally cushioned by a pad of fat. Significant weight loss can shrink that pad, narrowing the angle until the duodenum is pinched, causing a mechanical blockage: post-meal fullness, bilious vomiting and pain that eases in positions that open the angle.
Diagnosis and treatment routes
CT angiography demonstrates the compression and excludes other causes of obstruction. Treatment is usually conservative and succeeds in most: nutritional rehabilitation, small frequent meals, liquid supplements, or temporary tube feeding beyond the blockage, rebuilds the fat pad and relieves compression, with laparoscopic duodenojejunostomy reserved for persistent cases. In many parts of the UK, routine NHS referrals for this kind of problem currently take 20-45+ weeks, whereas an initial appointment with a private consultant is typically available within around two weeks.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a consultant upper GI surgeon. Your GP can refer you on the NHS, or you can arrange a private consultation directly.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any of the emergency symptoms described above.
Frequently asked
Common questions about Superior mesenteric artery syndrome.
Quick, plain-English answers to what people ask us most.
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Can you explain what superior mesenteric artery syndrome is?
Superior mesenteric artery syndrome is a medical condition that can affect people differently depending on severity, underlying cause and overall health. A clinician can confirm the diagnosis and explain what it means specifically for you.
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What causes superior mesenteric artery syndrome?
Causes vary and can include genetic, environmental, lifestyle and other health-related factors, and in some people no single clear cause is found. Your clinician can help identify anything relevant to your own case.
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What does superior mesenteric artery syndrome look like or feel like?
Symptoms vary between individuals and depend on which body systems are affected and how significant the underlying problem is. Keeping track of what you notice, and when, helps your clinician assess it accurately.
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Is superior mesenteric artery syndrome serious or dangerous?
Severity varies from mild and self-limiting to more significant, depending on the underlying cause and how it's managed. A clinical assessment is the best way to understand what it means in your specific situation.
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Is superior mesenteric artery syndrome hereditary or genetic?
This depends on the specific condition — some cases have a genetic or familial component, while others are linked more to environmental, lifestyle or other health factors. If you have a relevant family history, it's worth mentioning to your clinician.
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Can superior mesenteric artery syndrome be cured, reversed or prevented?
Many cases can be effectively treated or managed, and prevention strategies exist for some causes, though this depends on the specific underlying reason in your case. Your clinician can explain what's realistic for you.
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What treatment options are available for superior mesenteric artery syndrome?
Treatment is tailored to the underlying cause and severity, and can range from simple lifestyle or self-management measures to medical or specialist intervention.
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How long does superior mesenteric artery syndrome last, or take to recover from?
This varies depending on the underlying cause, how early it's identified, and how well it responds to treatment — your clinician can give a more specific expectation once assessed.
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When should specialist referral be considered for superior mesenteric artery syndrome?
Specialist referral is worth considering if symptoms persist, are getting worse, or aren't responding to initial treatment — your GP can help decide the right pathway and urgency.
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When should I see a doctor about superior mesenteric artery syndrome, and how quickly can I be seen privately?
See a doctor if symptoms are persistent, worsening, or affecting your daily life — earlier assessment generally leads to better management. NHS routine referrals for this kind of concern often take 20–45 weeks or longer depending on the area, while a private consultant can typically see you within about 2 weeks, with faster access to scans and specialist opinion.