My patient with pulmonary embolism also reports new-onset hiccups. Are the two conditions related?

Hiccups (AKA singultus) are due to the involuntary contraction of the inspiratory muscles, especially the diaphragm. The hiccup reflex involves an afferent limb ( eg, the phrenic and vagus nerves, sympathetic fibers from T6-T12,  brainstem) and an efferent limb, primarily the phrenic nerve1,2.  Thus, the irritation of any part of the arc in the head, neck, chest, or abdomen may potentially lead to hiccups.

Conditions involving the chest cavity that may be associated with hiccups include lung cancer, GERD, herpetic esophagitis, myocardial ischemia, bronchitis, empyema, lung masses, pneumonia, pleuritis, and pacemaker lead injury 1-3.

Reports of patients with PE and persistent hiccups (lasting longer than 48 h) have also appeared in the literature1,3. Of interest, in a report involving 3 patients, 2 had submassive or “large” PE, with one displaying the classic EKG changes of S1Q3T3; the size of PE in another was not reported1.  In another case report, PE was “not small” and involved the anterior and lateral lower lobe segments of pulmonary artery2.  Although the exact mechanism of PE causing hiccups is not clear, irritation of the afferent or efferent limb of the reflex arc in the chest has been postulated.  

If you liked this post, sign up under MENU and catch future pearls right into your inbox!


  1. Hassen GW, Singh MM, Kalantari H, et al. Persistent hiccups as a rare presenting symptom of pulmonary embolism. West J Emerg Med 202;13:479-483.
  2. Durning SJ, Shaw DJ, Oliva AJ et al. Persistent hiccups as the presenting symptom of a pulmonary embolism. Chest Disease Reports 2012;2:e2.
  3. Buyukhatipoglu H, Sezen Y, Yildiz A, et al. Hiccups as a sign of chronic myocardial ischemia. S Med J 2010;103: 1184-85.
My patient with pulmonary embolism also reports new-onset hiccups. Are the two conditions related?

How should I interpret an isolated elevated hemidiaphragm on chest x-ray?

In hospitalized patients, an elevated hemidiaphragm on chest x-ray is not a rare finding and is frequently asymptomatic. It has many potential causes, including lobar collapse or surgical resection of the lung, diaphragmatic eventration, distention of stomach or colon, or phrenic nerve paralysis (1).  

Among patients with a paralyzed hemidiaphragm, damage to the phrenic nerve caused by surgery (e.g. cardiac), mediastinal tumors, cervical spine pathology, diabetes, autoimmune (e.g. vasculitis) and infectious causes (e.g. herpes zoster and polio viruses) are often cited as potential causes; most may be idiopathic, however (1,2,3).

Chest x-ray has a high negative predictive value (93%) but a poor positive predictive value for diagnosis of hemidiaphragm paralysis (1).  When in doubt, the fluoroscopic “sniff” test should be used for confirmation.  

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.



1. Chetta A, Rehman AK, Moxham J, et al. Chest radiography cannot predict diaphragm function. Resp Med 2005;99:39-44

2. Curtis J, Nawarawong W, Walls J, et al. Elevated hemidiaphragm after cardiac operations: incidence, prognosis, and relationship to the use of topical ice slush. Annals of Thoracic Surgery 1989;48:764-8.

3. Crausman RS, Summerhill EM, McCool FD. Idiopathic diaphragmatic paralysis: Bell’s palsy of the diaphragm? Lung 2009;187:153-157.

Contributed by Ethan Balgley, Harvard Medical Student

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

How should I interpret an isolated elevated hemidiaphragm on chest x-ray?