Background. Dysfunctional breathing -vocal cord dysfunction (VCD) or paradoxical vocal fold movement (PVFM) is inappropriate vocal fold movement. Adduction of the vocal folds appears during inspiration, resulting in dyspnea and inspiratory and sometimes expiratory stridor, and acute upper airway obstruction. It is a functional disorder, an important mimicker of asthma, leading to unnecessary morbidity and high medical utilization, unnecessary drug use, and high-dose corticosteroid use. The gold standard test for diagnosis of VCD is direct visualization of the vocal folds by laryngoscopy while a patient has symptoms or is combined with special maneuvers that trigger symptoms. Methods. The recent papers on vocal cord dysfunction were reviewed. Results. VCD is an important differential diagnosis of refractory asthma, that is widely unrecognized. But concomitant vocal cord dysfunction and asthma are seen in a high degree of patients, up to 50%. VCD is a benign and self-limiting disorder and there are no long-term sequelae. Correct diagnosis is important due to proper treatment. The cornerstone of the VCD treatment is speech therapy like respiratory retraining, learning breathing techniques, and different maneuvers that enable quick release of symptoms. Psychotherapy and hypnosis are important modes of treatment as well. Medications and botulinum toxin are used rarely. Conclusions. We should suspect VCD in patients with asthma-like symptoms that do not respond to conventional asthma therapy or are induced by stress and exercise. A team of different specialists is necessary to find the correct diagnosis and proper treatment.