Ask the expert

Drinking cold water can help to disrupt a cycle of hiccups.
Drinking cold water can help to disrupt a cycle of hiccups.PHOTO: ST FILE

Q & A

Q Why do we have hiccups and does drinking water or holding your breath make them go away?

A A hiccup is a sudden, repetitive and involuntary contraction of the diaphragm.

The sudden and strong contractions of this breathing muscle rapidly suck in air which closes the voice box, creating the characteristic "hic" sound.

The exact mechanism which provokes hiccups is less clear. The current understanding is that irritation of certain nerves, such as the vagus nerve (a cranial nerve), triggers a hiccup reflex cycle which repetitively activates contraction of the diaphragm.

Many physical actions proposed to treat hiccups are based on the principle of disrupting this cycle. These include drinking cold water, which stimulates the vagus nerve, and holding your breath to disrupt the repetitive contraction.

Hiccups are very common and usually resolve spontaneously with no long-term detrimental effects. The most common causes are stretching of the stomach from eating large meals, taking carbonated drinks or swallowing air.

On rare occasions when hiccups are prolonged, lasting longer than 48 hours, you should consult a doctor as this may be caused by other more serious medical problems such as acid reflux, infection or cancer.

• Dr Wang Yu Tien, Consultant, Department of Gastroenterology and Hepatology, Singapore General Hospital

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A version of this article appeared in the print edition of The Straits Times on November 06, 2015, with the headline 'Ask the expert'. Print Edition | Subscribe