When a hiccup forms, it is because of a sudden, involuntary contraction of the diaphragm at the same time as a contraction of the voice box, or larynx, and a total closure of the glottis. This results in a sudden rush of air into the lungs, and the familiar "hic" sound.
The glottis is the middle part of the larynx, where the vocal cords are located.
Hiccups are medically known as synchronous diaphragmatic flutter or singultus (SDF). They can occur individually or in bouts. They are often rhythmic, meaning that the interval between each hiccup is relatively constant.
Most people have hiccups from time to time, and they usually resolve without treatment within a few minutes.
Rarely, there may be prolonged or chronic hiccups, which can last a month or more. Hiccups that last over 2 months are known as intractable hiccups.
If a bout lasts longer than 48 hours, this is considered persistent, and the person should see a doctor. It could be a sign of a more serious medical condition. This tends to be more common in men than in women.
The longest recorded case of hiccups lasted 60 years.
- The exact cause of hiccups remains unclear, but chronic hiccups are linked to a wide range of medical conditions, including stroke and gastrointestinal problems.
- Most cases resolve without treatment, but prolonged hiccups can lead to complications such as insomnia and depression.
- If hiccups last for longer than 48 hours, the person should see a doctor, who may prescribe muscle relaxants.
- Avoiding alcohol and not eating too quickly can help reduce the chance of hiccups.
Hiccups can occur after eating spicy food, drinking alcohol, and a range of other situations.
The National Organization for Rare Diseases (NORD) describes hiccups as "an involuntary spasmodic contraction of the muscle at the base of the lungs (diaphragm) followed by the rapid closure of the vocal cords."
A wide range of underlying conditions can trigger chronic or persistent hiccups.
Exactly how or why short bouts of hiccups happen remains unclear, but some factors have been associated with a higher risk of having them.
The following may trigger hiccups:
- hot or spicy food that irritates the phrenic nerve, which is near the esophagus
- gas in the stomach that presses against the diaphragm
- eating too much or Causing stomach distension
- drinking sodas, hot liquids, or alcoholic drinks, especially carbonated drinks
- experiencing stress or strong emotions
Some medications, such as opiates, benzodiazepines, anesthesia, corticosteroids, barbiturates, and methyldopa are known to cause hiccups.
Often, hiccups occur unexpectedly and neither the patient nor the doctor can identify their likely cause.
However, a number of medical conditions have been linked to chronic hiccups.
- gastrointestinal conditions, including inflammatory bowel disease (IBD), a small bowel obstruction, or gastroesophageal reflux disease (GERD)
- respiratory conditions, such as pleurisy of the diaphragm, pneumonia, or asthma
- excessive and habitual consumption of alcohol
- conditions that affect the central nervous system (CNS), including a traumatic brain injury (TNI), encephalitis, a brain tumor, or stroke
- conditions that irritate the vagus nerve, such as meningitis, pharyngitis, or goitre
- psychological reactions, including grief, excitement, anxiety, stress, hysterical behavior, or shock
- conditions that affect metabolism, including hyperglycemia, hypoglycemia, or diabetes
- liver and kidney problems
- cancer, either as a result of damage caused by the condition or as a side effect of treatment, such as chemotherapy.
- conditions of the autonomic nervous system, which also affects breathing, sweating, heartbeat, hiccups, and coughing
Most cases of hiccups will go away after a few minutes or hours with no medical treatment. If they persist, see your doctor.
Some tips may help, but their effectiveness is uncertain.
Tips for getting rid of hiccups
The following steps may help get rid of hiccups:
- Sip ice-cold water slowly or gargle with very cold water.
- Hold your breath for a short time, breath out, then do it again three or four times, and do this every 20 minutes.
- While you swallow, place gentle pressure on your nose.
- Place gentle pressure on your diaphragm.
- Bite on a lemon.
- Swallow some granulated sugar.
- Take a tiny amount of vinegar, just enough to taste.
- Breathe in and out of a paper bag, but never a plastic bag and never covering your head with the bag.
- Sit down and hug your knees as close to your chest as possible for a short time.
- Lean forward so that you gently compress your chest.
- Alternative therapies may include acupuncture and hypnosis.
- Gently pull on the tongue.
- Rub the eyeballs.
- Put your finger in your throat to trigger a gag reflex.
Many of these tips have been passed down through generations. They may be effective, but there is little research to support their use.
If a person has an underlying condition, managing the condition will probably resolve the hiccups.
If prolonged hiccups interfere with a person's quality of life, the doctor may prescribe a drug.
The following medications may help if there appears to be no underlying health condition:
- baclofen (Lioresal), a muscle relaxant
- gabapentin, an anti-seizure medication that is commonly prescribed for neuropathic pain, this can help alleviate the symptoms of hiccups
If these do not work, the following are recommended:
- chlorpromazine or haloperidol, antipsychotic medications that can alleviate hiccups
- metoclopramide (Reglan), an anti-nausea medication, that may help some people with hiccups
Ephedrine or ketamine can treat hiccups related to anesthesia or surgery.
The doctor will usually prescribe a low-dose, two-week course of medication. They may gradually increase the dosage until the hiccups are gone.
The course and dosage will depend on the severity of hiccups, the patients' general health, and their age.
In severe cases that have not responded to other treatment, a surgeon may inject medication into the phrenic nerve to temporarily block the nerve's action, or sever the phrenic nerve in the neck.
Prolonged hiccups can lead to complications such as:
- Weight loss and dehydration: If the hiccups are long-term and occur at short intervals, it can become difficult to eat properly.
- Insomnia: If prolonged hiccups persist during the sleeping hours, it can be hard to fall asleep or stay asleep.
- Fatigue: Prolonged hiccups can be exhausting, especially if they make it hard to sleep or eat.
- Communication problems: It can be difficult for the person to speak.
- Depression: Long-term hiccups can increase the risk of developing clinical depression.
- Delayed wound healing: Persistent hiccups can make it harder for post-surgical wounds to heal, increasing the risk of infections or bleeding after surgery.
Other complications include irregular heart beat and gastro-esophageal reflux (GERD).
Hiccups that last less than 48 hours do not usually need any medical attention, because they resolve on their own.
If they persist for longer, a doctor should be consulted.
The doctor may ask when the hiccups began, how often they occur, how frequent they are, whether they are happening all the time, and what a person was doing before they started.
They will probably perform a general physical examination and a neurological exam to check the person's:
- sense of touch
- muscle strength
- muscle tone
If an underlying condition may be the cause, the following tests may be ordered:
- blood tests, to check for infection, kidney disease or diabetes
- imaging tests, such as an x-ray, CT, or MRI scan, to assess for any anatomical abnormalities which may be affecting the phrenic or vagus nerves or the diaphragm
- endoscopic test, in which an endoscope, a flexible tube with a small camera at the end, is passed down the patient's throat to check the windpipe or esophagus
- en electrocardiogram (ECG), to check for heart-related conditions by measuring electrical activity in the heart
Some causes of hiccups are preventable.
Ways of reducing the risk include:
- avoiding sudden changes in temperature
- not drinking alcohol or sodas
- eating moderately and not too quickly
Most hiccups are brief and go away after a short while, but if they persist, or if you are concerned about other symptoms, you should see a doctor.