**1. Introduction**

Chronic cough is commonly reported symptoms in clinical practice. However, there is no globally accepted definition. Chronic, disruptive, lasting more than eight weeks cough is a difficult diagnostic and therapeutic problem [1]. The other used in researches definition of chronic cough is a cough lasting ≥3 months [2] or "daily coughing for at least 3 months duration during preceding 2 years [3]. Recently, replacing term chronic term by cough hypersensitivity syndrome has been proposed to highlight different phenotypes of this condition [4]. We can distinguish also idiopathic chronic cough and refractory chronic cough [5].

In approximation, it can affect 10–40% of general population [1, 3, 6].

The prevalence depend on sex, age and comorbidities. Recent observational study indicated that females, older adults, patients suffering from gastro-esophageal reflux disease, asthma, chronic obstructive pulmonary disease are at risk of chronic cough [3, 7]. Among additional risk factors are smoking [7] and drugs (e.g. angiotensin -converting enzyme inhibitors) [8].

People suffering from it require a multidisciplinary diagnostic panel like allergology tests, gastrological, pulmonary, otolaryngology and phoniatric counseling [1]. Despite enhanced diagnostics - the final diagnosis is difficult to be established, and the introduction of effective therapy sometimes impossible, which significantly reduces the quality of life in those patients [1, 9–11]. In practice, diagnosis of chronic cough raises difficulties cause cough can be symptom of disease from the one side, but from the other also consequence. Therefore carefully taken history provides information about potential causes. Clinical interview should aimed on exclusion malignancy, ongoing infection, body inhalation or using angiotensin converting enzyme inhibitors (ACE). Further question should focused on chronic pulmonary diseases, GERD, allergy [12]. The medical history should be deepen by different advanced methods like: chest CT or radiography, CT of sinusitis, spirometry, airway hypersensitivity test, allergic test, bronchoscopy, endoscopic examination of nose and paranasal sinuses, videolaryngostroboscopy, FEES, FVS, pH-metry, high resolution manometry, gastroscopy and functional assessment [5, 8]. Until recently, mainly pharmacological treatment was delivered. Results were promising although not free from side effects. The most often proposed pharmacological therapies include: proton pomp inhibitors and prokinetics agents, histamine H1 antagonists, inhaled corticosteroids and nasal steroids. In case of lack of therapeutic effect gabapentin, pregabalin are recommended. Other drugs like morphine, tramadol, codeine and dextromethorphan, amitriptyline are still controversial [12, 13]. Chronic cough treatment is still not well recognized, so the new pharmacological substance like Gefapixant are under investigation [14]. Recently physiotherapist and speech language therapist proposed several non-pharmacological treatment concentrated on breathing exercises and counseling. Following non-pharmacological components were indicated: education, psycho-educational counseling, vocal/ laryngeal hygiene and hydration, cough control/suppression techniques [5].

Despite cough is a natural defense mechanism of the airway, a little is known about chronic cough long term implications. Our clinical experience shows that the from the one side increased neck muscle tension leads to lowering the elevation of the larynx and impedes swallowing thus favoring retention of food, and food penetration or aspiration into the respiratory tract. But from the other side, delay opening upper esophageal sphincter. This in turn may result in further worsening of the symptoms causing persistent cough. The association of GERD and swallowing problems implicate the risk of microaspiration into the lungs what can trigger persistent cough. The little is known about prevalence of microaspiration as a consequence of chronic reflux disease [8].

To our best knowledge, there are no published studies referring to dysphagia in patients with chronic cough. Clinical experience shows that the increased neck muscle tension leads to lowering the elevation of the larynx and impedes swallowing thus favoring retention of food, and food penetration or aspiration into the respiratory tract. This in turn may result in further worsening of the symptoms causing persistent cough.

#### **2. Aim of study**

The aim of the study was to determine the prevalence of dysphagia in patients with chronic cough and its relationship with the long-term persistence of these symptoms.
