What Happens If You Swallow an Aluminum Can Tab?

Most swallowed aluminum can tabs pass through the digestive tract and come out the other end without causing any symptoms. The tab is small and lightweight, and the gut is built to move oddly shaped material along. But a can tab is not a smooth, round coin. It has thin edges, a rough stamped rim, and a shape that can catch on tissue, and in documented cases it has caused perforation, chronic obstruction, and even death. The combination of its sharp profile and the fact that aluminum is notoriously hard to spot on standard X-rays makes a swallowed tab a more complicated problem than it might seem.

The Typical Outcome

The gastrointestinal tract handles foreign objects more often than you might expect. People accidentally swallow small items regularly, and the vast majority travel from the esophagus through the stomach, into the small intestine, through the large intestine, and out in a bowel movement within a few days. A can tab, which weighs about a gram and measures roughly two centimeters long, usually follows this route without incident. You might never even notice it happened.

The stomach’s acid does not dissolve an aluminum tab in any meaningful way during the short time it spends there. Aluminum resists the stomach’s hydrochloric acid reasonably well, so the tab stays more or less intact as it moves through. In the best-case scenario, it slides through the pylorus (the exit of the stomach), navigates the winding small bowel, and passes without so much as a cramp. This is what happens in the majority of cases, and it is why emergency physicians do not always rush to intervene when someone reports swallowing one.

Why a Can Tab Is Not Like Swallowing a Coin

Coins are the most commonly swallowed foreign objects in children, and they almost always pass uneventfully because they are smooth, round, and unlikely to snag on anything. A can tab, by contrast, has features that make it more dangerous. The ring portion has a thin, stamped metal edge that can be surprisingly sharp, especially if the tab has been bent or partially torn from the can. The rivet end, where the tab was originally attached, can have a jagged nub. And the overall shape is irregular enough to catch on folds of tissue, particularly in the esophagus or the narrower sections of the small bowel.

Guidelines on managing swallowed foreign bodies generally treat sharp or pointed objects with more urgency than blunt ones, because they carry a higher risk of perforating the gut wall. Endoscopy literature notes that sharp and pointed foreign bodies are among the most difficult to manage and that practice runs with a replica of the object are sometimes essential before attempting removal.¹ A can tab falls into an uncomfortable middle ground: it is not a needle or an open safety pin, but it is not a smooth marble either. Its edges are just sharp enough to cause real damage if it lodges in the wrong spot.

Documented Complications

The medical literature includes case reports that illustrate what can go wrong when a tab does not pass cleanly. In one report, a young soldier presented with chronic abdominal pain that had been going on for some time. Imaging eventually revealed a foreign body stuck in his ileum, the final section of the small intestine, with a chronic stricture that had formed around it. Surgeons performed a mini-laparotomy and removed a segment of bowel, finding an embedded pop-tab surrounded by inflamed, scarred tissue.² That case is a useful illustration of what happens when a tab lodges somewhere it should not: the body walls it off with inflammation and scar tissue, which narrows the intestine and causes ongoing pain and potential obstruction.

The most alarming documented outcomes involve children. A report published in JAMA described one child who died after a swallowed tab created a fistula, an abnormal connection, between the esophagus and a branch of the aortic arch. Two other children in the same report suffered esophageal perforations that led to localized abscesses.³ A fistula between the esophagus and a major blood vessel is a life-threatening emergency, and while these cases are rare, they demonstrate that the worst-case scenario for a swallowed can tab goes well beyond a stomachache.

These severe complications tend to occur when the tab gets stuck in the esophagus rather than making it to the stomach. The esophagus is a narrow, muscular tube, and a lodged sharp object pressing against its wall can erode into adjacent structures over hours or days. Once a tab reaches the stomach, the risk drops considerably because the stomach is a much larger, more accommodating space. Still, as the soldier’s case shows, trouble can occur further downstream too.

Why Aluminum Is Difficult to See on X-Rays

One of the trickiest aspects of a swallowed can tab is finding it. Aluminum is much less dense than the metals typically picked up on standard X-rays. Coins, batteries, and steel objects show up clearly as bright white shapes on a radiograph, but a thin aluminum tab can blend right into the surrounding soft tissue. This means that a normal-looking X-ray does not reliably rule out the presence of a swallowed tab.

A cadaver study tested this directly by placing aluminum can tabs at the upper esophagus level in ten subjects. Two radiologists independently reviewed the images, and while one achieved about 80% sensitivity and the other about 90%, neither could catch every tab. The authors concluded that while aluminum tabs can sometimes be seen on plain films, the sensitivity is not high enough to completely exclude their presence.⁴ In other words, a negative X-ray does not mean a tab is not there.

A separate case report reinforced this point after neck and chest radiographs failed to reveal an aspirated aluminum foreign body at all. The authors emphasized that clinicians should have a low threshold for ordering a CT scan when an aluminum foreign body is suspected, because CT is far superior at detecting thin aluminum objects that plain films miss.⁵ If you go to the emergency room after swallowing a tab and the X-ray looks clean, that does not necessarily mean you are in the clear. A CT scan is the more reliable tool for this specific object.

A review of pediatric can-tab ingestions found that the tab could be identified on imaging in only about one in five cases, and all four instances where it was visible involved tabs sitting in the stomach, which is a relatively large and air-filled space that offers better contrast.⁶ When the tab is lodged in the esophagus or small bowel, surrounded by denser tissue, the odds of spotting it on a standard film drop even further.

Metal Detectors as a Screening Tool

Because aluminum is a metal, even though it does not show up well on X-rays, it can be detected by a handheld metal detector. This is a genuinely useful alternative, especially in a busy emergency room where imaging carries a wait time and a radiation dose. Studies have found that handheld metal detectors are accurate at identifying and localizing swallowed metallic foreign bodies, and researchers have proposed using them as an early screening tool in triage to speed up the decision about whether a patient needs further workup or can be safely observed.⁷

An earlier study specifically noted the value of metal detectors for picking up non-radio-opaque metallic foreign bodies like aluminum, finding a high detection rate when the history of swallowing was clear.⁸ This approach is not standard practice everywhere, but it neatly sidesteps the X-ray problem. A metal detector does not care about radiolucency; it detects metal directly. For a swallowed can tab specifically, this can be a faster and more reliable first step than plain radiography.

Children and Teenagers Are the Most Common Victims

Adults do swallow can tabs, sometimes accidentally while drinking and sometimes in psychiatric or correctional settings. But the published data skews heavily toward pediatric cases. Over a 16-year period at one institution, researchers identified 19 cases of stay-tab ingestion. The average age was about 8.5 years, but the majority were actually teenagers, and roughly four in five were over the age of five.⁶ This is not primarily a toddler-puts-everything-in-their-mouth problem. Older kids and teens seem to swallow tabs through a combination of playing with detached tabs, dropping them into the can, and accidentally swallowing them while drinking.

The risk profile is somewhat different in children than in adults. A child’s esophagus and intestinal tract are smaller, so a tab is proportionally larger and more likely to get stuck. The esophagus of a small child may be barely wider than the tab itself, and the esophageal walls are thinner and more vulnerable to perforation. The severe cases described in the JAMA report, including one fatality and two esophageal perforations with abscess formation, all involved children.³ Adults are not immune to complications, but the anatomy of a child’s upper GI tract makes lodging more likely and the consequences of lodging more dangerous.

What You Should Do If It Happens

If you or your child swallows a can tab, the first thing to assess is whether it feels stuck. Difficulty swallowing, a sensation of something caught in the throat, drooling, or refusal to eat (in a young child) all suggest the tab may be lodged in the esophagus. That is a situation that warrants an emergency room visit promptly, because an esophageal foreign body carries the highest risk of perforation and needs to be addressed quickly, usually within hours.

If the tab seems to have gone down smoothly and you feel fine, the situation is less urgent but still worth monitoring. Many emergency physicians recommend watchful waiting when a blunt or semi-sharp foreign body appears to have reached the stomach, because most will pass on their own. You should watch for symptoms over the following days: abdominal pain, vomiting, blood in the stool, or fever could indicate that the tab has caused a problem somewhere along the tract. Absence of symptoms over a few days, combined with eventual passage, is generally reassuring.

It is worth calling a doctor even if you feel fine, because the imaging issue matters here. As discussed, a plain X-ray may not show the tab, so if there is any doubt about where it is, a physician who understands aluminum’s radiolucency may recommend CT imaging rather than relying on a normal-looking X-ray to clear you.⁵ This is especially important for children, who may not articulate their symptoms clearly and in whom the risk of esophageal lodging is higher.

How Tabs End Up Getting Swallowed in the First Place

Modern beverage cans use “stay-on” tabs, which were designed specifically to reduce the litter and injury problems caused by the old fully detachable pull-tabs that dominated through the 1970s. Those older tabs separated completely from the can and were frequently discarded on the ground, where they cut bare feet and entered waterways. The stay-on design keeps the tab attached to the can after opening, which solved the litter problem but introduced a different one: people fidget with the tab, bend it back and forth until it detaches, and then drop it into the can or hold it in their mouth. Drinking from a can with a detached tab inside is one of the most common ways accidental ingestion happens, especially among teenagers.

The old fully detachable pull-tabs were recognized as a child health hazard decades ago. The JAMA report from 1976 specifically called them out as a danger, with the authors documenting severe injuries including the fatal aorto-esophageal fistula case.³ The shift to stay-on tabs reduced accidental ingestions significantly, but as the more recent pediatric case series shows, it did not eliminate them.⁶ The tab still detaches if you work at it, and people do.

When a Tab Lodges for Weeks or Months

One scenario that catches both patients and doctors off guard is the chronically retained tab. Unlike a coin, which tends to either pass quickly or get stuck immediately in a way that causes obvious symptoms, a can tab can lodge in the intestine and cause a slow-building problem. The soldier described in the ileal stricture case had been experiencing abdominal pain for an extended period before imaging finally revealed the embedded tab and the scar tissue that had formed around it.² The chronic inflammation and fibrosis narrowed the intestinal lumen enough to require surgical resection of the affected segment.

This kind of delayed presentation is hard to diagnose because the initial swallowing event may have been forgotten or dismissed as trivial. A patient showing up months later with intermittent belly pain and no memory of swallowing anything unusual is unlikely to be worked up for a foreign body on the first visit. The tab’s poor visibility on X-rays compounds the problem. CT scanning can find it, but only if a clinician thinks to look. In the soldier’s case, the diagnosis ultimately required both CT imaging and surgical exploration to confirm.

The pathology of the resected tissue showed benign tissue with swelling and chronic inflammation, not cancer or anything exotic. The body was simply reacting to a foreign object it could not expel. Left long enough, that reaction can produce a stricture tight enough to cause partial or complete bowel obstruction, which is a surgical emergency. This is the quiet danger of a tab that does not pass: not a dramatic perforation, but a slow, grinding inflammatory process that narrows the gut over time.

Aspiration Versus Ingestion

There is an important distinction between swallowing a tab into the esophagus and stomach versus accidentally inhaling it into the airway. Aspiration, where the tab enters the trachea and potentially lodges in a bronchus, is a separate and arguably more immediately dangerous event. A tab in the airway can obstruct breathing, cause persistent coughing, wheezing, or recurrent pneumonia. The medical literature includes cases of aspirated can tabs requiring bronchoscopic or surgical removal. This scenario is less common than GI ingestion but worth knowing about, because the initial symptoms of choking and coughing can overlap with the sensation of something “going down the wrong way,” and a person who aspirates a tab needs urgent airway evaluation rather than GI monitoring.

The imaging problem applies equally here. A tab lodged in a bronchus may not appear on a chest X-ray, and a normal-looking film can lead to a false sense of security. If someone chokes on a tab and develops persistent respiratory symptoms afterward, the same principle holds: CT is more reliable than plain radiography for finding thin aluminum objects, regardless of whether they ended up in the gut or the lungs.⁵

1
PubMed. Management of foreign bodies of the upper gastrointestinal tract: update
2
Radiology Case Reports. The aluminum beverage tab and a soldier with chronic abdominal pain
3
JAMA. Aluminum “Pop Tops”: A Hazard to Child Health
4
PubMed. Aluminum foreign bodies: do they show up on x-ray?
5
PubMed Central. Evaluation of suspected aspirated beverage can pull tab: radiographs may not be enough
6
PubMed. Beverage can stay-tabs: still a source for inadvertently ingested foreign bodies in children
7
PubMed. The utility of a handheld metal detector in detection and localization of pediatric metallic foreign body ingestion
8
PubMed Central. Metal detector and swallowed metal foreign bodies in children