This article originally appeared on RealSimple.com.
At best, hiccups are a nuisance. At worse, they could be a symptom of something seriously wrong. Luckily, it’s usually the former—a brief episode triggered by nerves or something you ate. But if hiccups persist for more than a few hours or if they show up frequently, it may be worth getting checked out by a doctor.
Before we get into the scary stuff, though, it may help to understand exactly what hiccups are. A hiccup is an involuntary spasm of the diaphragm, the muscle between your chest and your abdomen. The diaphragm usually expands down and contracts back up smoothly as you breathe, but it can jerk down suddenly if it becomes irritated.
That sudden jerk triggers a closure of the glottis, the slit-like opening between the vocal cords and the voice box. “You quickly swallow air and your voice box shuts, and that’s what causes that hiccupping sound,” says Roshini Rajapaksa, M.D., a gastroenterologist at NYU Langone Medical Center and Health magazine’s medical editor.
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Lots of things can cause the diaphragm to become irritated, from a larger-than-normal meal, to sudden temperature changes, to the carbonated bubbles in soda. Alcohol, cigarette smoke, and swallowed air (while chewing gum, for example) are also likely culprits. Even feelings of stress or nervousness can set off a bout of hiccups. “And sometimes they can come out of the blue,” says Dr. Rajapksa.
Irritation to the vagus nerve or phrenic nerves, which run from your sinuses down to the diaphragm, can also trigger hiccups. That means that a sore throat or an ear infection—or even a hair touching your eardrum—can be to blame.
Most hiccups only last a few minutes or hours. When they last more than 48 hours, they’re known as persistent hiccups; when they last more than 30 days, they’re called intractable hiccups. You should see a doctor if your hiccups last more than a couple of days—they can not only begin to interfere with eating, sleeping, and mental well being, but they can also signal a hidden health condition. In severe cases, hiccups can even cause nerve damage.
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If you’re a heavy drinker or smoker, cutting back on these habits could help reduce your hiccups. Your doctor may also look for signs of gastroesophageal reflux disorder (GERD), also known as acid reflux, which is a treatable condition and a common cause of hiccups.
In rare cases, hiccups can be caused by nerve damage or by a tumor in the stomach or neck. “There’s also an area of the brain involved with the hiccup reflex, so rarely a condition in the brain, like an infection or a mass, can cause them, too,” says Dr. Rajapksa. Hiccups can also indicate a stroke or heart problem, according to Texas A&M University, and a few cases have been associated with serious blood clots.
Finally, hiccups may be a side effect of advanced diseases like cirrhosis (scarring of the liver), or liver or kidney failure. But usually they’ll occur along with other hard-to-miss symptoms—like fatigue, nausea, and swelling of the legs and abdomen—so it’s unlikely that hiccups would be the first indication that something is wrong.
Obviously, working with a doctor to address any serious underlying causes is the best way to treat hiccups that last for longer than a few days. But if you know you’re in good health and you really just need relief right now, Dr. Rajapksa says there are a few things you can try: “Sometimes drinking cold water or gargling with cold water can help, because it stimulates the back of your throat,” she says. “Holding your breath also works for some people.” If your hiccups become uncomfortable and painful or won’t go away on their own, doctors can prescribe muscle-relaxing medicines that can help.