What Is a Nasogastric Tube and How Is It Inserted?

A nasogastric tube is a thin, flexible tube passed through the nose, down the throat, and into the stomach. It serves two broad purposes: delivering nutrition, fluids, or medications directly to the stomach when a patient cannot swallow safely, and draining or decompressing the stomach when its contents need to come out. Despite being one of the most common procedures in hospitals, nasogastric tube placement carries real risks, demands careful verification, and is often more uncomfortable than patients expect. The science behind when to use one, how to confirm it is in the right place, and when to consider alternatives has evolved considerably in recent years.

Why Nasogastric Tubes Are Used

The reasons for placing a nasogastric tube fall into a few main categories. Feeding is the most familiar: when someone cannot eat by mouth due to a stroke, surgery, neurological condition, or prolonged illness, a nasogastric tube provides a short-term route for liquid nutrition.¹ Decompression is equally important. In cases of bowel obstruction, for example, the stomach and intestines fill with gas and fluid that have nowhere to go. A nasogastric tube connected to suction relieves that pressure, easing pain and reducing the risk of vomiting.² Nasogastric tubes also serve as a delivery route for medications when a patient cannot swallow pills, and occasionally for diagnostic purposes such as checking for bleeding in the stomach.

That said, the decision to place one is not always straightforward. A study examining patients with small bowel obstruction who were not actively vomiting found that those who received nasogastric decompression actually had a significantly higher risk of pneumonia and respiratory failure, along with longer hospital stays, compared to patients managed without a tube.³ The takeaway is that nasogastric tubes are not a reflexive intervention; they should be placed when there is a clear clinical need, not just out of habit.

How the Tube Is Inserted

Insertion is conceptually simple but practically tricky. The patient typically sits upright with their chin slightly tucked toward their chest. A lubricated tube is advanced through one nostril, past the back of the throat, down the esophagus, and into the stomach. Patients are usually asked to swallow sips of water during the process to help guide the tube past the airway and into the food pipe instead. The whole procedure takes a few minutes, but it can feel much longer to the person on the receiving end.

One of the most critical decisions during insertion is how far to advance the tube. Too short, and the tip sits in the esophagus where feeding could cause aspiration. Too long, and it can loop or pass into the small intestine. The traditional method for estimating the right length involves measuring the distance from the tip of the nose to the earlobe and then down to the bottom of the breastbone, a technique called NEX. Research has consistently shown that NEX tends to underestimate the distance needed, leaving the tube tip too high.⁴ Modified approaches, such as adding ten centimeters to the NEX measurement, have demonstrated accuracy as high as about 97% in placing the tube tip correctly within the stomach.⁵ Despite this evidence, the unmodified NEX method remains widely taught and used in many settings.

In children, measurement is even more variable because of the range of body sizes involved. Some pediatric protocols extend the measurement from nose to earlobe to a point midway between the bottom of the breastbone and the belly button, a method called NEMU, to try to account for shorter torsos.⁶ Pediatric misplacement carries the same dangers as in adults, and in very small patients the margin of error is tighter.

Confirming the Tube Is in the Right Place

Getting a nasogastric tube into the stomach is one thing. Proving it got there is another, and this verification step is arguably the most safety-critical part of the entire process. A tube that ends up in the lungs instead of the stomach can cause pneumonia, lung collapse, or death if feeding or medication is delivered through it. Several methods exist to check placement, and they vary enormously in reliability.

The gold standard is a chest X-ray. It lets clinicians see the tube’s path and confirm the tip is sitting below the diaphragm and within the stomach. But X-rays have drawbacks: they take time, expose the patient to radiation, and interpretation is not always straightforward. A review of X-ray verification noted that while X-rays catch a high percentage of unsafe placements, reading the image can be difficult even with standardized criteria, and a post-placement X-ray cannot prevent a tube from being placed deep into the lung in the first place.⁷ In pediatric settings, radiographs remain the standard confirmation method, though pH testing of aspirated fluid is the most commonly used evidence-based bedside check.⁸

pH testing works by withdrawing a small amount of fluid through the tube and measuring its acidity. Stomach acid is highly acidic, so a low pH reading suggests the tip is in the stomach. A study found that when the aspirate pH was 5.5 or below, the tube was in the stomach about 99% of the time, with a sensitivity of roughly 78% and specificity of about 86%.⁹ A decision-analysis study found that pH cutoffs of 5 and 6 scored highest for overall safety when balancing the need to correctly identify tubes in the stomach while excluding those outside it.¹⁰ The main limitation is that you cannot always get an aspirate sample, especially with small-bore tubes, and acid-suppressing medications can raise gastric pH enough to produce ambiguous readings.

One older method that stubbornly persists in some clinical settings is the “whoosh test,” or auscultatory method, where air is injected through the tube while someone listens over the stomach with a stethoscope. The sound of air entering the stomach can be mimicked by air entering the esophagus or even the lungs, or by bowel sounds, leading to false reassurance about correct placement.¹¹ Most guidelines now recommend against relying on it, yet it continues to be taught and used informally, which is a genuine patient safety concern.

Pain and Discomfort During Insertion

Ask anyone who has had a nasogastric tube placed, and they will likely describe it as one of the most unpleasant parts of their hospital stay. The tube passing through the nose and throat triggers a strong gag reflex, watering eyes, and an uncomfortable sensation of pressure. Patients frequently rate the experience as more distressing than they anticipated, and repeated insertions make the experience worse, not better.

Lidocaine, a local anesthetic, is the most studied intervention for easing this discomfort. It can be delivered as a gel in the nostril, a spray to the back of the throat, or sometimes both. A meta-analysis found that lidocaine produced a significant reduction in patient-reported pain scores during insertion.¹² Despite this evidence, lidocaine is not universally used before insertion, partly because of time pressure in emergency settings and partly due to inconsistent protocols across hospitals. If you or a family member is about to undergo the procedure, it is reasonable to ask whether a local anesthetic can be applied first.

Beyond the insertion itself, having a tube in place for days or weeks creates ongoing irritation. Sore throat, nasal erosion, sinusitis, and difficulty speaking or swallowing around the tube are all common complaints. Some patients, particularly those who are confused or agitated, repeatedly pull at the tube, leading to accidental removal and the need for reinsertion. A simple device called a nasal bridle, which loops a thin piece of tape or tubing around the nasal septum and secures the tube from behind, has been used effectively to prevent self-removal without causing significant discomfort.¹³

Complications and Risks

The most feared complication of nasogastric tube insertion is pulmonary misplacement, where the tube enters the airway and ends up in a lung. If feeding or fluids are delivered through a misplaced tube, the consequences range from chemical pneumonitis to life-threatening pneumothorax. This risk is highest in patients who are sedated, have a reduced gag reflex, or are on mechanical ventilation, because the normal protective reflexes that would trigger coughing when something enters the airway may be blunted.

Aspiration, where stomach contents travel backward into the lungs, is another major risk even when the tube is correctly placed. The presence of a nasogastric tube compromises the natural barriers against reflux. A tube sitting across the junction between the esophagus and stomach disrupts both the upper and lower esophageal sphincters, increases the frequency of involuntary sphincter relaxations, and blunts the throat’s natural protective closure reflex.¹⁴ A meta-analysis of aspiration risk in patients receiving nasogastric feeding identified several independent risk factors: the number of other medical conditions, history of prior aspiration, use of sedatives, how deeply the tube was placed, the volume of residual stomach contents, level of consciousness, and age.¹⁵

Other complications include nasal tissue damage, especially with prolonged use; sinusitis from blocking normal sinus drainage; esophageal erosion or ulceration; and electrolyte imbalances when the tube is used for sustained gastric suctioning. Most of these risks increase with time, which is why nasogastric tubes are generally considered a short-term solution.

Delivering Medications Through a Nasogastric Tube

When patients cannot swallow pills, clinicians often crush tablets and dissolve them in water for delivery through the tube. This sounds straightforward, but it introduces a surprisingly complex set of problems. Not all medications can be safely crushed. Extended-release formulations, enteric-coated tablets, and certain chemotherapy drugs are designed to release their active ingredients slowly or in specific parts of the gut. Crushing them can dump the entire dose at once, alter how the body absorbs the drug, or expose the stomach lining to compounds meant to bypass it entirely. Improper crushing can also reduce the actual dose a patient receives if medication sticks to the syringe, tubing, or mortar.¹⁶

Pharmacists play a critical role here, reviewing medication lists to flag drugs that should not be crushed and recommending liquid alternatives or substitute medications when available. Tube clogging is another practical headache; thick suspensions or poorly dissolved tablets can block the lumen, requiring the tube to be flushed aggressively or, in some cases, replaced entirely. Flushing with warm water before and after each medication is standard practice, but even that does not always prevent blockages, especially with small-bore feeding tubes.

When to Switch to a Longer-Term Option

Nasogastric tubes are meant for temporary use, typically days to a few weeks. When it becomes clear that a patient will need tube feeding for a longer period, the conversation shifts to a gastrostomy tube, which is placed through the abdominal wall directly into the stomach, usually via a minimally invasive endoscopic procedure. The decision to transition is not purely about a calendar deadline. A survey of clinicians found that the highest-ranked factors in recommending the switch were exceeding the expected duration for temporary feeding and the anticipated need for an extended feeding period.¹⁷

For patients and families, the idea of a more “permanent” tube can feel alarming. In practice, gastrostomy tubes tend to be more comfortable than nasogastric tubes once the insertion site heals, and they eliminate the ongoing nasal and throat irritation. They also carry a lower risk of accidental dislodgement and aspiration compared to a tube running through the nose. The trade-off is that gastrostomy placement is a procedure requiring sedation and carries its own small risk of infection, bleeding, or organ injury.

Nasogastric vs. Nasojejunal Feeding

Sometimes feeding needs to bypass the stomach altogether, particularly in conditions where the stomach is inflamed or not emptying properly. A nasojejunal tube follows the same path through the nose but extends past the stomach into the upper small intestine. In severe acute pancreatitis, for instance, the thinking has long been that feeding into the jejunum might avoid stimulating the pancreas. But a Cochrane review found no clear difference in mortality or other major outcomes between nasogastric and nasojejunal feeding in this population, though the certainty of the evidence was very low.¹⁸

A more recent meta-analysis added some nuance: while mortality remained similar between the two approaches, the nasogastric group showed higher rates of diarrhea, pain, and infection compared to nasojejunal feeding.¹⁹ Nasojejunal placement is technically harder and often requires endoscopic or fluoroscopic guidance, adding cost and complexity. For now, the choice between the two often comes down to the clinical scenario and the resources available at a given hospital rather than a clear winner in the evidence.

Ethical Considerations in Advanced Illness

One of the most emotionally charged questions around nasogastric tubes arises in advanced dementia and end-of-life care. When a person with severe cognitive decline stops eating, family members and clinicians face the question of whether to start tube feeding. The impulse is understandable: no one wants to feel that a loved one is starving. But the evidence on outcomes is sobering. Tube feeding in advanced dementia has not been shown to prolong life, prevent aspiration pneumonia, or improve quality of life. It can, however, cause discomfort, require physical restraints to prevent the patient from pulling the tube out, and shift care toward a more medicalized trajectory.

A review of the ethical landscape around enteral feeding in advanced dementia emphasized that the decision to initiate tube feeding should be collaborative, involving physicians, family members, and, when possible, the patient, with the patient’s best interests always at the center.²⁰ Advance directives that specifically address artificial nutrition can spare families from making these decisions under crisis conditions. If you have aging parents or loved ones with progressive neurological conditions, this is a conversation worth having early.

Tube Materials and Design

Modern nasogastric tubes come in a range of sizes and materials, and the choice matters more than you might think. Large-bore tubes, generally above 14 French in diameter, are made of stiffer polyvinyl material. They are easier to place accurately, less prone to clogging, and more reliable when clinicians need to aspirate stomach contents to check residual volume. They are the go-to for decompression and drainage. Small-bore tubes, typically 8 to 12 French, are made of softer materials like silicone or polyurethane, making them more comfortable for patients who need feeding over several days. However, their flexibility means they require a guidewire or stylet during insertion to maintain enough stiffness to navigate the nasal passage, and that guidewire introduces its own risks if it punctures tissue or if the tube is advanced over a kinked wire.²¹

The trend in recent decades has been toward smaller, softer tubes for feeding to improve patient comfort, but this comes with trade-offs in reliability. Smaller tubes clog more easily, are harder to aspirate for pH testing, and can be more difficult to visualize on X-ray. Clinicians often have to balance what is best tolerated against what is easiest to monitor and maintain.

Emerging Verification Technologies

Given the limitations of X-rays and pH testing, researchers have been exploring bedside technologies that could confirm tube position in real time during insertion. One of the most promising approaches uses magnetic tracking. A small magnet is built into the tube tip, and an external sensor on the patient’s chest follows its path as the tube is advanced. A pilot study in healthy volunteers found that magnetic tracking achieved 100% accuracy in determining whether the tube tip was above or below the diaphragm, matching both manometry and fluoroscopy.²²

Translating that accuracy to actual patients has proven harder. A clinical trial of a low-cost magnet-tracking device in hospitalized patients found that the tracked tube location deviated from the X-ray position by an average of roughly half a centimeter to just over one and a half centimeters in the subjects where tracking worked well, and the device successfully detected the tube’s downward turn past the bottom of the breastbone in half of the patients tested.²³ The technology is still in early stages, and body habitus, patient positioning, and ambient electromagnetic interference all affect performance. But the appeal is clear: real-time, radiation-free confirmation at the bedside would eliminate delays, reduce X-ray exposure, and potentially catch misplacements before any feeding begins. Electromagnetic tracking systems are already used commercially in some countries, though they are not yet standard of care in most hospitals.