Hiccups are repeated involuntary spasms of the diaphragm followed by a quick closing of the vocal cords. The spasms occur between normal breaths and make a distinctive sound. The diaphragm is the thin muscle below the lungs and heart that separates the chest cavity from the abdomen. It is the main muscle used in breathing. Hiccups may also be called singultus or hiccough.
The exact cause of hiccups is not known. People with cancer may have hiccups for no obvious reason, but they may be related to:
- some brain tumours
- esophageal cancer
- stomach cancer
- pancreatic cancer
- tumours of the mediastinum, which is the space in the chest between the lungs, breastbone and spine
- lung cancer
- bowel obstruction
- surgery to the abdomen
- some medicines
Hiccups may be due to irritation of the nerve that controls the diaphragm. This irritation can be caused by:
- tumour growth
- enlarged liver
- buildup of fluid in the abdomen, or ascites
- extra air in the stomach, or gastric distension
- inflammation of the esophagus, or esophagitis
Symptoms of hiccups can vary depending on their cause and other factors. They usually happen occasionally for short periods of time. Hiccups that last longer are described according to how long they last:
- acute hiccups last up to 48 hours
- persistent, or protracted, hiccups last longer than 48 hours
- intractable hiccups last longer than 1 month
If symptoms get worse or don’t go away, report them to your doctor or healthcare team without waiting for your next scheduled appointment.
If your hiccups are acute, your doctor will ask some questions about your medical history and do a physical exam. You may need to have the following tests if your hiccups last a long time and don’t have an obvious cause:
- blood chemistry tests
- chest x-ray
- electrocardiogram (ECG)
- endoscopy of the esophagus, stomach and upper small intestine
- chest CT scan
- brain MRI
Find out more about these tests and procedures.
Once the cause of hiccups is known, your healthcare team can suggest ways to manage them. They may prescribe medicines or place a nasogastric (NG) tube if your hiccups are severe, very distressing or last longer than a few days. An NG tube is a flexible tube passed through the nose, down the throat and esophagus, and into the stomach. The tube is removed as soon as the hiccups stop.
You can also try the following to relieve hiccups:
- Breathe slowly and deeply into a paper bag.
- Slowly drink a glass of cold water.
- Eat a teaspoon of sugar.
- Hold your breath for as long as you can.