Hiccups are repetitive, uncontrollable contractions of the diaphragm. Your diaphragm is the muscle just below your lungs. It marks the boundary between your chest and abdomen. The diaphragm regulates breathing. When your diaphragm contracts, your lungs take in oxygen. When your diaphragm relaxes, your lungs release carbon dioxide.
The diaphragm contracting out of rhythm causes hiccups. Each spasm of the diaphragm makes the larynx and vocal cords close suddenly. This results in a sudden rush of air into the lungs. Your body reacts with a gasp, creating the sound characteristic of hiccups.
Singultus is the medical term for hiccups.
There is no way to anticipate hiccups. With each spasm, there usually is a slight tightening of the chest or throat prior to your making the distinctive hiccup sound.
Most cases of hiccups start and end abruptly, for no discernable reason. Episodes generally last only a few minutes. Hiccups that last longer than 48 hours are considered persistent. Hiccups that last longer than two months are considered intractable, or difficult to manage.
Numerous causes of hiccups have been identified. However, there is no definitive list of triggers. Hiccups often come and go for no apparent reason.
The most common causes of short-term hiccups include:
- eating spicy food
- consuming alcohol
- drinking carbonated beverages, such as sodas
- consuming very hot or very cold foods
- a sudden change in air temperature
- excitement or emotional stress
- aerophagia (swallowing too much air)
Hiccups that last longer than 48 hours are categorized by the type of irritant that caused the episode. In some cases, episodes can last for weeks. Hiccups that last for more than two months are considered intractable.
The majority of persistent hiccups are caused by injury or irritation to either the vagus or phrenic nerve. The vagus and phrenic nerves control the movement of your diaphragm. These nerves may be affected by:
- irritation of your eardrum, which may be caused by a foreign object
- throat irritation or soreness
- goiter (enlargement of the thyroid gland)
- gastroesophageal reflux (stomach acid backing up into the esophagus)
- an esophageal tumor or cyst
Other causes of hiccups may involve the central nervous system (CNS). The CNS consists of the brain and spinal cord. If the CNS is damaged, your body may lose the ability to control hiccups. CNS damage that may lead to persistent hiccups includes:
- multiple sclerosis (a chronic nerve disease)
- meningitis and encephalitis (infections that can cause swelling in the brain)
- head trauma or brain injury
- hydrocephalus (accumulation of fluid on the brain)
- neurosyphilis and other brain infections
Hiccups that last for longer periods also can be caused by:
- overuse of alcohol
- tobacco use
- an anesthesia reaction after surgery
- certain classes of drugs, including barbiturates, steroids, and tranquilizers
- an electrolyte imbalance
- kidney failure
- arteriovenus malformation (a condition in which arteries and veins are tangled in the brain)
- cancer and chemotherapy treatments
- Parkinson’s disease (a degenerative brain disease)
Sometimes, a medical procedure can accidentally cause you to develop long-term hiccups. They can be caused by procedures used to treat or diagnose other conditions, including:
Hiccups can occur at any age. They can even occur while a fetus is still in the mother’s womb. However, there are several factors that can increase your likelihood of developing hiccups.
You may be more susceptible if you:
- are male
- experience intense mental or emotional responses, ranging from anxiety to excitement
- have received general anesthesia (you were put to sleep during surgery)
- had surgery, especially abdominal surgery
Most hiccups are not an emergency. However a prolonged episode can be uncomfortable and disruptive to daily life. Contact your physician if you have hiccups that last longer than two days. Your doctor can determine the severity of your hiccups in relation to your overall health and other conditions.
There are numerous options for treating hiccups. Typically, a short-term case of hiccups will take care of itself. However, the discomfort may make waiting out hiccups unbearable if they last longer than a few minutes.
The following treatments for hiccups can be tried at home:
- Breathe into a paper bag.
- Eat a teaspoon of granulated sugar.
- Hold your breath.
- Drink a glass of cold water.
- Pull on your tongue.
- Lift your uvula with a spoon. Your uvula is the fleshy piece of tissue that is suspended above the back of your throat.
- Attempt to purposefully gasp or belch.
- Bring your knees to your chest and maintain this position.
- Try a valsalva maneuver by holding your breath and bearing down.
- Relax and breathe in a slow, controlled manner.
If you still have hiccups after 48 hours, talk to your doctor. Your physician may attempt gastric lavage (stomach pumping) or carotid sinus massage (rubbing the main carotid artery in the neck).
If the cause of your hiccups is unclear, your physician may recommend tests. These can help detect any underlying disease or condition. The following tests may be useful in determining the cause of persistent or intractable hiccups:
- blood tests to identify signs of infection, diabetes, or kidney disease
- liver function tests
- imaging of the diaphragm with a chest X-ray, computed tomography (CT) scan, or magnetic resonance imaging (MRI) scan
- echocardiogram to assess heart function
- endoscopy, which utilizes a thin, lighted tube with a camera on the end to investigate your esophagus, windpipe, stomach, and intestine
- bronchoscopy, which utilizes a thin, lighted tube with a camera on the end to examine your lungs and airways
Treating any underlying causes of your hiccups will usually make them go away. If persistent hiccups have no obvious cause, there are several medications that may be prescribed. The more commonly used drugs include:
- chlorpromazine and haloperidol (antipsychotic medications)
- benzodiazepines (a class of tranquilizers)
- metoclopramide (a nausea drug )
- baclofen (a muscle relaxant)
- nifedipine (a blood pressure medication)
- seizure medications, such as gabapentin
There are also more invasive options, which can be used to end extreme cases of hiccups. They include:
- nasogastric intubation (insertion of a tube through your nose into your stomach)
- an anesthetic injection to block your phrenic nerve
- surgical implantation of a diaphragmatic pacemaker. This is a battery-powered device that stimulates your diaphragm and regulates breathing.
A long-term episode of hiccups can be uncomfortable and even harmful to your health. If left untreated, prolonged hiccups can disturb your sleeping and eating patterns, leading to:
- weight loss
There is no proven method for preventing hiccups. However, if you experience hiccups frequently, you can try to reduce your exposure to known triggers.
The following may help reduce your susceptibility to hiccups:
- Don’t overeat.
- Avoid carbonated beverages.
- Protect yourself from sudden temperature changes.
- Don’t drink alcohol.
- Remain calm, and try to avoid intense emotional or physical reactions.