A nasogastric (NG) tube is a flexible plastic tube inserted through the nose, down the throat and esophagus, and into the stomach. It’s one of the most common devices used in hospitals, serving two broad purposes: draining the stomach of air and fluid, or delivering nutrition and medication directly to it. If you or someone you know has been told they need one, here’s what to expect.
Why NG Tubes Are Used
NG tubes fall into two main categories based on what they’re designed to do. The first is decompression, which means relieving pressure in the stomach and intestines. When a bowel obstruction, surgical complication, or a condition called ileus (where the gut temporarily stops moving) causes gas and fluid to build up, an NG tube connected to gentle suction can drain that buildup and ease pain, nausea, and vomiting.
The second major use is feeding and medication delivery. When someone has a functioning digestive system but can’t safely swallow (after a stroke, for instance, or while on a ventilator), an NG tube lets liquid nutrition and crushed medications bypass the mouth and throat entirely. This is a form of enteral feeding, meaning food still goes through the gut rather than being delivered intravenously. NG tubes placed in ventilated patients also help prevent stomach contents from backing up into the lungs.
Types of NG Tubes
The type of tube used depends on its purpose. For stomach decompression, the standard choice is a double-lumen tube (often called a Salem Sump). It has two channels inside: a large one for suctioning fluid and a smaller one that acts as a vent, preventing the tube from latching onto the stomach wall during suction.
For feeding and medications, smaller, softer single-lumen tubes are preferred because they’re more comfortable for longer use. A Levin tube is the simplest version, just a narrow flexible tube. A Dobhoff tube is similar but has a small weight at the tip to help guide it into position. These thinner tubes are gentler on the nose and throat, which matters when someone needs one for days or weeks.
How an NG Tube Is Inserted
Before insertion, the care team measures how much tube needs to go in. The standard method is called NEX measurement: the distance from the nose to the earlobe, then from the earlobe down to the bottom of the breastbone. This gives an estimate of how far the tube must travel to reach the stomach. Some clinicians measure in reverse (breastbone to ear to nose) because the breastbone landmark can be easier to locate first.
The tube is lubricated and gently fed through one nostril, down the back of the throat, and into the esophagus. You’re usually asked to sit upright and take small sips of water through a straw to help the tube slide down. The whole process typically takes just a few minutes, but it is uncomfortable. A numbing agent applied to the nose and throat beforehand can reduce pain by roughly 26%, according to a meta-analysis of clinical trials. Both gel and spray forms are effective, and gel tends to be preferred by patients. If you’re getting an NG tube placed, it’s reasonable to ask whether a topical anesthetic will be used.
Confirming the Tube Is in the Right Place
Getting the tip into the stomach (and not accidentally into the lungs) is critical. The gold standard for confirming placement is a chest X-ray, which clearly shows where the tube tip sits. A faster bedside option is testing the pH of fluid drawn back through the tube. Stomach acid typically has a pH of 5.5 or lower, so a reading in that range suggests correct placement.
The pH method avoids radiation exposure and is cheaper, but it isn’t always straightforward. With smaller feeding tubes, it can be difficult to pull back enough fluid for a reliable reading. When there’s any doubt, an X-ray is used to confirm. An older technique, listening with a stethoscope while pushing air through the tube, is no longer considered reliable and has been phased out of most guidelines.
What It Feels Like to Have One
The insertion itself is the most unpleasant part. Most people describe a gagging sensation as the tube passes through the back of the throat, along with pressure in the nose and watery eyes. Once in place, the tube is taped to the nose and cheek. You’ll likely feel a mild irritation in the throat, especially when swallowing, but it becomes less noticeable over time. The tube doesn’t prevent you from talking, though your voice may sound slightly different.
During feeding, the head of the bed is elevated to at least 30 degrees. This position helps prevent stomach contents from traveling backward into the esophagus and lungs, a complication known as aspiration. Aspiration pneumonia is one of the more serious risks of tube feeding, with reported rates varying widely depending on the patient population. Keeping the bed elevated is one of the simplest and most effective ways to lower that risk.
Ongoing Care and Maintenance
NG tubes can clog, especially when used for feeding or medication. To prevent blockages, nursing staff flush the tube with water at least once per shift, before and after intermittent feedings, at regular intervals during continuous feedings, and before and after giving medications. The standard flushing fluid is plain water. Cranberry juice and carbonated drinks, despite old advice suggesting otherwise, actually make clogs worse because their acidity causes proteins in feeding formulas to clump inside the tube. If a clog does develop and water doesn’t clear it, enzyme-based solutions or specialized declogging kits are used.
Medications given through an NG tube need to be in liquid form or thoroughly crushed and dissolved. Some pills, particularly extended-release or enteric-coated formulations, can’t be crushed, so your care team may need to switch to alternative forms.
Risks and Complications
Most NG tubes are placed without serious problems, but the procedure does carry risks. The most common issues are throat soreness, minor nosebleeds, and sinus discomfort. More significant complications include the tube accidentally entering the airway instead of the esophagus (which is why placement verification is so important), irritation or erosion of the nasal passages with prolonged use, and aspiration pneumonia from tube feeding.
Certain conditions make NG tube placement unsafe or significantly riskier. Severe facial or skull base fractures can cause the tube to enter the brain cavity instead of the esophagus. Recent surgery on the esophagus or stomach, large varicose veins in the esophagus (common in advanced liver disease), and certain narrowing or blockages in the nasal passages are also situations where alternatives to a standard NG tube would be considered.
How Long NG Tubes Stay In
NG tubes are designed for short-term use. For stomach decompression after surgery, they may be needed for only a day or two. For feeding, they can remain in place for several weeks, though the tube is typically replaced periodically to reduce irritation and infection risk. If someone needs tube feeding for longer than four to six weeks, a different approach is usually recommended, such as a tube placed directly through the abdominal wall into the stomach, which is more comfortable for extended use.