Hiccup is caused by excitation of the phrenic reflex arc or by suppression of higher centers by central lesions or metabolic abnormalities. The sound is produced by a spasm of the inspiratory muscles that is abruptly terminated by glottis closure.
Recurrent or intractable hiccups should prompt a more thorough investigation. Hiccup with dysphagia suggests esophageal cancer, achalasia, or hiatal hernia.
Following are the causes of hiccup
- Benign
- Drugs
- Vagal stimulation
- Post-operative
- Pneumonia
- Subdiaphragmatic abscess
- Pericarditis
- Uremia
- Central
- Hysterical
- Splenic infarction
- Thoracic aortic aneurysm
- Liver metastasis
- Lung cancer
- Esophageal cancer
- Diagnostic Approach
Benign causes of hiccup
Self-limited hiccups occur in an healthy patient and it may
be initiated by laughter or by gastric distension due to overeating or
aerophagia.
Drugs producing hiccup
Alcohol, general anesthesia, barbiturates, benzodiazepines,
dexamethasone, and methyldopa can
produce causes.
Vagal stimulation
A foreign body in contact with the tympanic membrane of ear can
irritate the auricular branch of the vagus. Pharyngitis, laryngitis, or neck tumors
can stimulate the recurrent laryngeal branchto produce hiccup.
Post-operative hiccup
Hiccups may be the result of general anesthesia itself or of
diaphragmatic irritation with upper abdominal surgery.
Pneumonia
Hiccups are caused by inflammation of diaphragm so there is usually pleuritic
chest pain in the setting of cough, fever, and a pleural rub.
Subdiaphragmatic abscess
Suspect with abdominal pain which radiates to the shoulder
and is associated with fever and localized upper abdominal tenderness.
Pericarditis
It is marked by chest pain relieved by leaning forward, and
a two-or three-component friction rub, especially in the setting of myocardial
infarction.
Uremia
The uremia is usually severe enough to cause a metabolic
encephalopathy with asterixis.
Central
These hiccups are recognized by concomitant neurological
findings. The most common central nervous system causes are encephalitis,
brainstem tumor, basilar meningitis, and multiple sclerosis.
Hysterical hiccup
This type of hiccup
stops during sleep.
Splenic infarction
Hiccups accompany acute left upper quadrant abdominal pain.
There is an embolic source, such as atrial fibrillation, endocarditis, or
sickle cell anemia.
Thoracic aortic aneurysm
Otherwise asymptomatic unless there is a dissection.
Liver metastasis
Suspect metastases if a primary cancer is known, but hiccups
may be the presenting symptom. A firm mass is palpable in the right upper
quadrant.
Lung cancer
Mediastinal adenopathy impinges on the phrenic nerve.
Smoking history and hemoptysis are important clues.
Esophageal cancer
A tumor in the distal one-third of the esophagus is
suggested by hiccups associated with dysphagia
