Causes of hiccups 

Hiccups occur when your diaphragm (the thin layer of muscle that separates your chest cavity from your abdomen) suddenly and involuntarily contracts (tightens).

As your diaphragm contracts, it causes you to breathe air in very quickly. The incoming air is stopped when your glottis (the opening between your vocal cords) closes suddenly, producing the characteristic sound of a hiccup.

Causes of short-term hiccups

Most cases of hiccups occur for no apparent reason. Everyone experiences a short bout of hiccups from time to time. This is perfectly normal and nothing to be concerned about.

In some cases however, short-term hiccups may appear to have a specific trigger, such as:

  • drinking alcohol
  • smoking
  • having a bloated stomach
  • eating too quickly or eating spicy foods
  • drinking hot or fizzy drinks
  • swallowing air – for example, while chewing gum
  • a sudden change in room temperature
  • a sudden change in the temperature inside your stomach – for example, eating something hot followed by a cold drink
  • emotions, such as stress, fear or excitement

People experiencing short-term hiccups usually pass without the need for treatment.

Causes of long-lasting hiccups

In rare cases, hiccups that last 48 hours or longer can be caused by an underlying condition or a medication you are taking, although in many cases a cause is not identified.

Underlying conditions

Some of the conditions that can cause long-term hiccups include:


Persistent hiccups can sometimes also be caused by a reaction to certain types of medication, such as:

  • anaesthesia – medication given before a surgical operation or procedure that causes a loss of sensation or consciousness
  • corticosteroids – medication that reduces inflammation (swelling)
  • benzodiazepines – a type of sedative that helps to reduce anxiety
  • barbiturates – a type of sedative sometimes used to prevent seizures (fits)
  • opioids – medication used to treat pain; morphine and methadone are both strong opioids
  • methyldopa – medication used to treat high blood pressure (hypertension)
  • chemotherapy medications – medicines used to kill cancer cells

If an underlying cause of long-lasting hiccups can be identified, treating this cause can help improve the problem.

Read more about treating hiccups.

Page last reviewed: 15/09/2014

Next review due: 15/07/2017