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Diaphragmatic Paralysis Clinical Presentation

  • Author: Nader Kamangar, MD, FACP, FCCP, FCCM; Chief Editor: Ryland P Byrd, Jr, MD  more...
Updated: Apr 10, 2015


Bilateral diaphragmatic paralysis is characterized by profound abnormalities of pulmonary and respiratory muscle function. Patients develop severe restrictive ventilatory impairment, and the vital capacity and total lung capacity frequently are below 50% of predicted for that patient. Lung capacity is reduced further when the patient assumes the supine position. Symptoms depend on whether the paralysis is unilateral or bilateral, how rapid the paralysis occurs, and the presence of underlying pulmonary disease.

Unilateral diaphragmatic paralysis

Unilateral diaphragmatic paralysis is often discovered incidentally in patients undergoing chest radiography for some other reason. Patients usually are asymptomatic at rest but may experience dyspnea upon exertion and may have a decrease in exercise performance.[5]

If the patient has an underlying lung disease, dyspnea may occur at rest.

Some patients may develop orthopnea, which is generally less intense than patients bilateral diaphragmatic paralysis.

Bilateral diaphragmatic paralysis

Patients typically present with respiratory failure or dyspnea (may be misinterpreted as a sign of heart failure) that worsens in the supine position.[1] Tachypnea and rapid, shallow breathing occur when the patient adopts the recumbent position.

Patients also report anxiety, insomnia, morning headache, excessive daytime somnolence and fatigue, and poor sleep habits. In some patients, nonspecific GI symptoms such as heartburn, regurgitation, nausea, and epigastric pain can also develop.[4]



Physical examination findings depend on whether the paralysis is unilateral or bilateral. Generally, a breathing pattern of paradoxical abdominal wall retraction during inspiration occurs. The physician can evaluate the patient further by palpating under the costal margin and feeling for the descending hemidiaphragms during inspiration.

Unilateral diaphragmatic paralysis

Patients reveal dullness to percussion and absent breath sounds over the lower chest on the involved side. Excursion on the involved hemithorax is decreased when compared with the healthy side.

Bilateral diaphragmatic paralysis

Patients report morning headaches, confusion, and signs of cor pulmonale. Chest examination reveals limitation of diaphragmatic excursions and bilateral lower chest dullness with absent breath sounds. Patients are tachypneic and use accessory respiration muscles. The diagnostic finding is a paradoxical inward movement of the abdomen with inspiration.



Unilateral diaphragmatic paralysis

The most common diagnosed cause is a malignant (ie, metastatic lung cancer) lesion leading to nerve compression (approximately 30% of patients).

If malignancy is not the cause, many times the etiology cannot be determined.

Other causes in the differential include blunt cervical trauma, surgical trauma (mainly thoracic), herpes zoster, cervical spondylosis, and supraclavicular brachial plexus block (which can be largely avoided with the use of ultrasound.) Upper cervical radiculopathies as a cause of Hemidiaphragmatic paralysis have also been reported.[6]

Bilateral diaphragmatic paralysis

The most common causes are secondary to motor neuron disease, including amyotrophic lateral sclerosis and postpolio syndrome.

Other causes include thoracic trauma (including cardiac surgery),[7] multiple sclerosis, myopathies, muscular dystrophy (acid maltase deficiency), Guillain-Barré syndrome, and Parsonage-Turner syndrome (neuropathy of brachial plexus).

Contributor Information and Disclosures

Nader Kamangar, MD, FACP, FCCP, FCCM Professor of Clinical Medicine, University of California, Los Angeles, David Geffen School of Medicine; Chief, Division of Pulmonary and Critical Care Medicine, Vice-Chair, Department of Medicine, Olive View-UCLA Medical Center

Nader Kamangar, MD, FACP, FCCP, FCCM is a member of the following medical societies: Academy of Persian Physicians, American Academy of Sleep Medicine, American Association for Bronchology and Interventional Pulmonology, American College of Chest Physicians, American College of Critical Care Medicine, American College of Physicians, American Lung Association, American Medical Association, American Thoracic Society, Association of Pulmonary and Critical Care Medicine Program Directors, Association of Specialty Professors, California Sleep Society, California Thoracic Society, Clerkship Directors in Internal Medicine, Society of Critical Care Medicine, Trudeau Society of Los Angeles, World Association for Bronchology and Interventional Pulmonology

Disclosure: Nothing to disclose.


Shahriar Pirouz, MD Resident Physician, Department of Internal Medicine, Olive View-UCLA Medical Center

Disclosure: Nothing to disclose.

Payam Rohani, MD Resident Physician, Department of Internal Medicine, Olive View-UCLA Medical Center

Payam Rohani, MD is a member of the following medical societies: American College of Physicians

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Daniel R Ouellette, MD, FCCP Associate Professor of Medicine, Wayne State University School of Medicine; Chair of the Clinical Competency Committee, Pulmonary and Critical Care Fellowship Program, Senior Staff and Attending Physician, Division of Pulmonary and Critical Care Medicine, Henry Ford Health System; Chair, Guideline Oversight Committee, American College of Chest Physicians

Daniel R Ouellette, MD, FCCP is a member of the following medical societies: American College of Chest Physicians, Society of Critical Care Medicine, American Thoracic Society

Disclosure: Nothing to disclose.

Chief Editor

Ryland P Byrd, Jr, MD Professor of Medicine, Division of Pulmonary Disease and Critical Care Medicine, James H Quillen College of Medicine, East Tennessee State University

Ryland P Byrd, Jr, MD is a member of the following medical societies: American College of Chest Physicians, American Thoracic Society

Disclosure: Nothing to disclose.


Sat Sharma, MD, FRCPC Professor and Head, Division of Pulmonary Medicine, Department of Internal Medicine, University of Manitoba; Site Director, Respiratory Medicine, St Boniface General Hospital

Sat Sharma, MD, FRCPC is a member of the following medical societies: American Academy of Sleep Medicine, American College of Chest Physicians, American College of Physicians-American Society of Internal Medicine, American Thoracic Society, Canadian Medical Association, Royal College of Physicians and Surgeons of Canada, Royal Society of Medicine, Society of Critical Care Medicine, and World Medical Association

Disclosure: Nothing to disclose.

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Acute unilateral left diaphragmatic paralysis in a patient with moderately severe chronic obstructive pulmonary disease. The patient previously was asymptomatic but developed class III dyspnea following the new event.
Fluoroscopy of elevated left hemidiaphragm in a patient with unilateral diaphragmatic paralysis. The diaphragm moves paradoxically upward during inspiration.
Fluoroscopy of elevated left hemidiaphragm in a patient with unilateral diaphragmatic paralysis. The diaphragm does not move during expiration. For confirmation, a sniff test is required.
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