Hiccups are repeated spasms or sudden movements of the diaphragm that you can't control. The diaphragm is the muscle that separates your chest from your stomach area and plays an important role in breathing. A spasm in your diaphragm causes your vocal cords to suddenly close, producing a "hic" sound.
Eating a large meal, drinking alcoholic or carbonated beverages, or getting excited suddenly may cause hiccups. In some cases, hiccups may be a sign of an underlying medical issue. For most people, hiccups usually last only a few minutes. Rarely, hiccups may continue for months. When they last that long, they can result in weight loss and extreme tiredness.

Spasms of your diaphragm that you can't control cause hiccups. The diaphragm is the muscle that separates your chest from your stomach area and plays an important role in breathing. This spasm causes your vocal cords to close briefly, producing a "hic" sound.
Symptoms include uncontrolled spasms in your diaphragm and a "hic" sound. Sometimes you may feel a slight tightening sensation in your chest, stomach area or throat.
Make an appointment to see your health care provider if your hiccups last more than 48 hours or if they're so severe that they cause issues with eating, sleeping or breathing.
The most common triggers for hiccups that last less than 48 hours include:
Issues that may cause hiccups to last more than 48 hours include nerve damage or irritation, central nervous system disorders, metabolic issues, and certain drug and alcohol problems.
A cause of long-term hiccups is damage to, or irritation of, the vagus nerves or phrenic nerves. These nerves supply the diaphragm muscle.
Factors that may damage or irritate these nerves include:
A tumor or infection in your central nervous system or damage to your central nervous system due to an injury can disrupt your body's normal control of the hiccup reflex.
Examples include:
Long-term hiccups may result when your body's metabolism doesn't work properly.
Examples of metabolic issues include:
Use of certain drugs or problems with alcohol may cause long-term hiccups.
Examples include:
Males are much more likely to develop long-term hiccups than females. Other factors that may increase your risk of hiccups include:
Ongoing hiccups may interfere with eating, drinking, sleeping and speaking. Hiccups also can worsen pain.