Original Research

Sigh syndrome: Is it a sign of trouble?

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Sigh syndrome, which involves irrepressible, persistent sighing, may be stressful for the patient, but it’s benign.



Practice recommendation
  • Sigh syndrome is a genuine medical diagnosis with distinct criteria, conferring significant stress for those affected. Despite outward signs of an abnormal breathing pattern, this symptomatology is unrelated to any respiratory or organic pathology.
  • Ancillary testing and medication seem unnecessary; supporting reassurance appears sufficient, since the syndrome has a favorable outcome.

Objective The goal of this study was to identify the characteristics and clinical course of patients presenting with considerable stress regarding irrepressible persistent sighing, and to determine whether any association exists between this syndrome and respiratory or other organic disease during the acute or follow-up period.

Study design We conducted a case series review of patients diagnosed with a defined symptom complex and gathered relevant data.

Population Forty patients who presented to 3 clinics in Israel met our 10 criteria for sigh syndrome: recurrent sighing (at least once a minute, for varying lengths of time throughout the day); otherwise shallow respiration; patient conviction that deep breaths are obstructed; intensity of episodes provokes stress leading to consultation; no obvious trigger; episodes last a few days to several weeks; no interference with speech; sighing is absent during sleep; no correlation with physical activity or rest; and self-limited.

Outcomes measured We assessed demographic and health status information, as well as recent circumstances that could have served as triggers for the symptoms. We also performed systematic diagnoses of acute and chronic organic disease.

Results Physicians diagnosed “sigh syndrome” in 40 subjects (19 men [47.5%]), mean age 31.8 years, during the 3-year study period. All patients conformed to 10 sigh syndrome criteria. In 13 patients (32.5%), a significant traumatic event preceded onset of symptoms. Ten (25%) had previous anxiety or somatoform-related disorders. For 23 patients (57.5%), the sigh syndrome episode repeated itself after an initial episode. We found no association in any of the cases with any form of organic disease. Likewise, during the follow-up period (on average, 18 months), we did not observe the development of a specific organic disorder in any case.

Conclusions The “sigh syndrome” runs a benign course; it mainly demands the support and understanding of the treating physician to allay any patient concerns.

In our clinical practices, we have repeatedly cared for patients who came into our clinics because of a worrisome irregular breathing pattern characterized by a deep inspiration, and followed by a noisy expiration. We have referred to the set of clinical signs that these patients present with as “sigh syndrome.”

We have long suspected that sigh syndrome is an underdiagnosed and self-limited condition that is often mistaken for a serious respiratory disorder. In our experience, this syndrome runs a benign course. However, we believed that this syndrome had characteristic and consistent features, and should not be considered a diagnosis of exclusion.

Thus, we undertook a study to observe a group of subjects with these features to judge whether this subjectively alarming symptom complex is in fact harmless, and whether it is appropriate to respond to it as we had, by taking a stress-alleviating approach alone.

What is sigh syndrome?

Patients with sigh syndrome exhibit a compulsion to perform single but repeated deep inspirations, accompanied by a sensation of difficulty in inhaling a sufficient quantity of air. Each inspiration is followed by a prolonged, sometimes noisy expiration—namely, a sigh. Observing such abnormal breaths and confirming that the patient feels a concomitant inability to fill his lungs to capacity is sufficient to make the diagnosis.

This breathing compulsion is irregular in nature: It may occur once a minute or several times a minute, and this breathing pattern may continue—on and off throughout the day—for a few days to several weeks. In our experience, it provokes significant anxiety in patients, prompting them to seek medical advice. It does not occur when the patient is asleep, and it is not triggered by physical activity.

Both patient and doctor may, at first, be convinced that the problem reflects a serious illness. The 10 features of sigh syndrome (TABLE 1) constitute a proposed definition. All of our study subjects exhibited these 10 features.

10 features of sigh syndrome

  1. Recurrent, forced deep inspiration (one or more times per minute, continuing for varying lengths of time throughout the day), followed by a prolonged and often audible sigh
  2. Otherwise shallow respiration
  3. Patient believes that each deep breath is obstructed in some way
  4. Intensity of episodes provokes ample stress, leading the patient to seek medical attention
  5. Spontaneous episodes; usually no obvious trigger or provocation
  6. Episodes last a few days to several weeks
  7. No interference with speech; conversation is normal between the deep breaths and sighs
  8. Sighing is absent during sleep
  9. There is no correlation with physical activity or rest
  10. Self-limited; responds well to reassurance.

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