Diagnosing hiccups

Hiccup bouts are more common than persistent and intractable hiccups, and do not require an in-depth and detailed medical examination. However, chronic hiccups (persistent and intractable hiccups) require a more thorough and detailed evaluation in order for the underlying cause (i.e. aetiology) to be determined so as to design a successful treatment plan.

A number of disorders that lead to chronic hiccups may be diagnosed by means of a thorough physical examination and medical history, bearing in mind that, for a number of patients, the specific cause is not always determined⁸.

Medical history

A medical history may include an enquiry into details concerning the duration and severity of the hiccups experienced, any medical conditions that may be a possible cause, previous surgery, illicit drug and alcohol use, as well as a review of all medications currently being taken.

Experts note that persistent hiccups that are also experienced during sleep suggest that the cause is organic as opposed to psychogenic⁹.

**My Med Memo – Organic disorders are a result of physiological issues that are caused by damage done to the brain such as brain trauma or disease.

Physical examination

During a physical evaluation, a doctor is likely to assess the external auditory (i.e. ear) canals to eliminate any potential irritants (i.e. foreign bodies or infections) of the eardrums, also known as the tympanic membranes, which may irritate the vagus nerve, as an underlying cause.

A thorough head and neck evaluation is also vital to rule out an enlarged thyroid or lymphadenopathy, which is a disease of the lymph nodes. Other vital components of a physical exam may include a neurological evaluation (i.e. an examination of the nervous system conducted with instruments such as reflex hammers and lights – this does not result in any pain), which also includes an assessment of the cranial nerves.

In addition, a doctor will listen to the patient’s breathing with a stethoscope, this is known as a chest auscultation, and also conduct an examination of the abdomen, palpating (i.e. examining by touch) for any lesions.

Laboratory tests

There are a number of lab tests that a doctor may conduct should one suffer from persistent or intractable hiccups. These tests will help to determine whether hiccups are a symptom of an underlying cause and obtain the following information:

• CBC (complete blood count) – This blood test evaluates overall health and is able to detect a wide variety of different disorders.
• BUN (blood urea nitrogen) – This test, which involves analysis of a blood sample, measures nitrogen levels within the blood to determine the level at which the kidneys are functioning.
• Electrolytes – These are minerals such as calcium, potassium, bicarbonate and sodium that are found in the body. A blood sample will be taken to determine if there are any underlying conditions, such as heart or lung disease that may be causing an electrolyte imbalance.
• Creatinine – Should the kidneys not be functioning correctly, this may result in a high level of creatinine found in the blood, creatinine is a waste product that forms naturally when muscle tissue breaks down, it is filtered through the kidneys and then excreted through urine.
• Calcium – Measuring the levels of calcium found in the blood helps to detect a number of health conditions pertaining to the bones, heart, nerves and kidneys.
• Liver function tests – A group of blood tests that determine whether there are any abnormalities present such as inflammation or cell damage in the liver.
• Amylase/lipase – These tests are used to detect issues with the pancreas, more specifically, pancreatitis, which is inflammation of the pancreas. Amylase is an enzyme found in the pancreas that aids in the digestion of carbohydrates. Lipase is also a pancreatic enzyme and helps to break down and digest body fats from fatty acids.

Additional testing

Additional tests may also be performed if specific risk factors or symptoms are present. If a patient is at risk of cardiovascular disease, then a doctor is likely to perform an electrocardiogram in order for possible myocardial ischemia (i.e. coronary artery disease refers to damage to or disease within the major blood vessels of the heart) to be evaluated.

If a patient is experiencing difficulty breathing, known as dyspnoea, then a chest computed tomography scan (chest CT) or a chest radiograph may be conducted to detect whether any mediastinal (i.e. the space in the chest between the lungs) or pulmonary (relating to the lungs) abnormalities that may be irritating the vagal or phrenic nerves or diaphragm exist.

If your doctor detects any oesophageal symptoms or dysphagia (difficulty swallowing), then he or she may perform an upper endoscopy in order to check for possible malignancies (i.e. cancerous tumours), oesophageal stricture (i.e. inflammation of the oesophagus as a result of stomach acid irritation leading to narrowing or tightening of the oesophageal tissues) and oesophagitis (inflammation of the oesophagus).

Other tests and studies that may be considered include:

• MRI - Magnetic resonance imaging of the head may be conducted if a patient exhibits neurological symptoms or progressive headaches.
• Lumbar puncture – This is also known as a spinal tap and involves a needle being inserted into the lower part of the spine in order for a sample of cerebrospinal fluid to be obtained should a doctor suspect there are any central nervous system infections present such as meningitis.
• Bronchoscopy – This procedure allows a doctor to examine a patient’s airways through the use of a bronchoscope if he/she exhibits pulmonary symptoms or if any lesions are detected through imaging tests.
• Oesophageal manometry – This test is used to evaluate swallowing in cases of dysphagia that is unable to be explained through an endoscopy. Oesophageal manometry makes use of a thin, flexible tube that is inserted through an anaesthetised nostril, down the throat and into the oesophagus as the patient swallows.
• Pulmonary function tests (PFT) – These tests measure the functioning of the lungs should the patient experience wheezing or shortness of breath that cannot be explained by other tests.

If a patient has advanced cancer, the exact cause of chronic hiccups tends to be multifactorial and requires a lengthy and thorough evaluation for the cause to be detected. Even when an exact cause is established, it is unlikely to change the way in which hiccups are managed. Due to this, doctors will typically focus on treating symptoms as opposed to performing extensive examinations and tests.

 

 

^References: 

^{8. NCBI. 1995. Hiccups. Available: https://www.ncbi.nlm.nih.gov/pubmed?term=7839159 [Accessed 27. 02. 2017]}

^{9. NCBI. 2011. Persistent Hiccups (Singultus) as the Presenting Symptom of Medullary Cavernoma. Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3244169/ [Accessed 27. 02. 2017]}