Coughing is a coordinated reflex work of the airways to try to expel unwanted waste from the body, such as aspirated foreign bodies or particulate matter, secretions accumulated by various infections, postnasal drip, or irritation of irritating foods. These wastes can sometimes originate from the upper respiratory tract as well as from the lungs. Expulsion of nasal discharge in the throat or sputum in the bronchi are provided by similar mechanisms.


If you have a cough that lasts longer than a week, if you have shortness of breath, if you have chest pains, if your cough does not go away despite taking medication, if you cough up sputum, if you see blood in your sputum, if you have a headache when coughing, if you have a fever or if you experience a few of these symptoms, consult your doctor.

What is cough?

Coughing is a coordinated reflex work of the airways to try to expel unwanted waste from the body, such as aspirated foreign bodies or particulate matter, secretions accumulated by various infections, postnasal drip, or irritation of irritating foods. These wastes can sometimes originate from the upper respiratory tract as well as from the lungs. Expulsion of nasal discharge in the throat or sputum in the bronchi are provided by similar mechanisms. Cough is a protective mechanism of the body. Because this mechanism is weakened in neonates, the elderly, those with paralysis or a neuromuscular disease, the likelihood of lung infections or aspiration pneumonia increases in these individuals.

If the cough lasts less than 3 weeks, it is classified as acute cough, if it lasts between 3-8 weeks, subacute cough, and if it lasts longer than 8 weeks, it is classified as chronic cough. In addition, cough is divided into productive cough if it is phlegmatic, and non-productive if it is dry.

Acute cough is usually caused by an irritation in the upper airways. Chronic cough, on the other hand, may occur mostly after esophageal diseases, rhinitis, asthma, obstructive pulmonary diseases or infection.

The vast majority of patients admitted to the hospital due to cough are women. The most common cause of cough in children is viral infections.

How does cough occur?

Cough receptors are stimulated by various inflammatory, irritant or mechanical foreign bodies in the airways. These stimuli are mechanical (dust, mucus or foreign body, etc.), chemical (citric acid, capsaicin, tataric, acidic or alkaline solutions, saline, nicotine in cigarette smoke, osmotic agents, etc.), inflammatory (histamine, bradykinin, PGE2, PGF2alpha, etc.). .) it could be. The type of cough varies according to the area stimulated by these substances and the duration of exposure. If these stimuli are in the upper respiratory tract up to the larynx, the stimulus causes coughing by exhaling directly. However, in stimuli below the larynx, a cough reflex occurs by taking a deep breath first. Pneumothorax, lobar infiltration, atelectasis, and cough rarely occur in irritation of the bronchi and alveoli because there are no cough receptors in the lung parenchyma. Irritation caused by chemical stimuli is perceived by the unmyelinated C fibers in the entire respiratory system and delivered to the cough center and initiates coughing.

Neurons originating from the cough receptors reach the nucleus tractus solitarius in the brain stem via the vagus nerve and then the cough center. The cough center in the brain stem sends messages to the cough producing muscles and coordinates the cough mechanism. The part up to this point is the involuntary cough mechanism. Sometimes people can cough intentionally and on purpose. This voluntary cough works with a mechanism controlled from the cortex of the brain and stimulates the cough center in the brain stem.

How is cough evaluated?

Cough is a rare symptom in healthy people. Many conditions must be interpreted together for the evaluation of cough. These:

  • Duration of cough
  • Character of cough
  • Whether accompanied by sputum
  • Nature of sputum
  • Relationship of cough with time of day
  • Factors affecting cough
  • Additional diseases
  • Drugs used (ACE inhibitors)
  • Smoking status

All of these conditions are questioned and interpreted in the patient who comes with the complaint of cough.

Acute cough

All causes of shortness of breath can also cause acute cough. There may even be an acute cough without shortness of breath. Acute cough is a cough that lasts up to 3 weeks.

The most common causes of acute cough are:

  • Common cold
  • Acute bronchitis
  • Acute sinusitis
  • Acute exacerbations of chronic obstructive pulmonary disease
  • Allergic rhinitis
  • Irritant substances
  • Bordatella pertussis infection
  • Asthma
  • Pneumonia
  • Aspiration
  • Pulmonary embolism
  • Medicines
  • Left heart failure

If a patient with acute cough has coughing up blood (hemoptysis), shortness of breath, fever, chest pain, hoarseness, weight loss, suspicion of foreign body aspiration or lung cancer, it is absolutely necessary to evaluate with chest X-ray.

Cold and cough

The common cold is the most common cause of acute cough. More than 200 viruses can cause the common cold. Rhinoviruses are the most common cause of the common cold. Secondly, there is the Coronavirus. Parainfluenza virus, Rhinosyncytial virus, Adenovirus and Enteroviruses are among the viruses that cause common cold. After the first ten days, only bacterial infections can be added to the table.

Epithelial damage in the respiratory tract may not be seen from time to time in the common cold, but enlargement of the vessels (vasodilation) and increased secretion occur. The resulting postnasal discharge triggers the patient’s desire to clear the throat and cough. Sneezing is also common.

Acute bronchitis and cough

In acute bronchitis, cough lasting up to 3 weeks is often seen with or without sputum. The most common causes of acute bronchitis are respiratory viruses. Additional common ones are Influenza A and B, Parainfluenza virus, Rhinosyncytial virus and SARS. Only one in ten cases of acute bronchitis can be bacterial.

Epithelial and mucosal damage in acute bronchitis leads to temporary narrowing of the bronchi and temporary hyperreactivity, together with a decrease in partial aeration capacity.

Patients with acute bronchitis should be evaluated for acute pneumonia, acute asthma attack, or other acute lung disease if the heart rate is greater than 100, the fever exceeds 38 degrees, the respiratory rate is above 24/min, and abnormalities in breath sounds are noticed.

Subacute cough

Cough lasting more than 3 weeks and lasting up to 8 weeks is referred to as subacute cough. The most common cause is a cough that continues after infections. Asthma, sinusitis, continued exposure to allergens or continued exposure to irritants may also present as subacute cough. It usually continues after upper respiratory tract infections. There are no findings on chest radiographs. It is a self-limiting condition.

Bacterial infections may also develop on the damaged mucosa after upper respiratory tract infections. Bacteria such as Mycoplasma pneumonia or Bordatella pertussis can cause these infections.

Bordatella pertussis is a highly contagious microorganism. It causes whooping cough. Although the vaccine is administered as a mixed vaccine in childhood, its protection is for 10 years and it is beneficial to repeat it every ten years. It usually causes coughs that are common among students living in the same house and in the same school. It can cause coughing fits. Vomiting after fever and cough can cause a tickling sensation in the throat. Antibiotic treatment is required. Macrolide antibiotics are preferred. These patients should be isolated at home for at least 5 days.

Chronic cough

Cough lasting longer than 8 weeks is called chronic cough in patients who do not smoke, are not exposed to irritants, do not use drugs such as ACE inhibitors, have no abnormality in the immune system and have a normal chest X-ray.

The most common causes of chronic cough in adults are:

  • Angiotensin Converting Enzyme Inhibitor drug use
  • Exposure to smoking or other irritants
  • Upper airway chronic cough syndrome
  • Asthma
  • Non-asthmatic eosinophilic bronchitis
  • Gastroesophageal reflux
  • Postinfectious cough
  • Tuberculosis
  • Bronchiectasis
  • Lung cancer
  • Lung abscess
  • Foreign body aspiration
  • Sarcoidosis
  • Interstitial lung diseases
  • Psychogenic cough

The most common causes of chronic cough are upper respiratory tract cough syndrome, asthma and reflux.

What is upper respiratory cough syndrome?

Sinusitis, allergic or non-allergic rhinitis, vasomotor rhinitis, postinfectious rhinitis or is a condition that is common in people exposed to environmental irritants and causes chronic cough. It can be accompanied by a runny nose, runny nose, cough that starts at night, and cough that increases when you get up in the morning. Antihistamines and decongestants are used in its treatment.

Asthma and chronic cough

The only asthma with cough symptoms is cough variant asthma. Cough variant asthma is the cause of nearly a quarter of undiagnosed coughs. In these patients:

  • Non-productive cough lasting longer than 8 weeks
  • Shortness of breath and no wheezing
  • Having a postnasal drip
  • Normal respiratory air capacity of the lungs
  • Positive bronchial provocation test
  • Chest radiograph is normal
  • Positive response with inhaled steroids or bronchodilator drugs are important conditions for diagnosis.

In these patients, cough is usually the only symptom, and there is usually a cough that increases at night. The severity of cough, which increases with cold or exercise, is variable.

While evaluating these symptoms, other possible diseases should also be questioned in the patient. For example, pathologies in the large airways, diseases affecting the lung parenchyma, extrapulmonary causes and other psychogenic causes may also experience discomfort with a similar cough picture.

Nonasthmatic eosinophilic bronchitis and chronic cough

Nearly one-third of chronic cough, which is usually seen in middle-aged patients with only cough, without smoking or atopic allergic background, is nonasthmatic eosinophilic bronchitis. Eosinophils appear in sputum or bronchial lavage. Respiratory function tests and chest X-rays are normal in these patients. Bronchial provocation tests are also negative. Similarly, these patients also get a positive response from inhaled steroids.

atopic cough

It is an isolated chronic cough. Chest radiographs or respiratory tests are also normal in these patients. There is no obstruction in the airways. There are also no signs of hypersensitivity in the airways. However, positivity in allergy skin tests, elevated IgE levels in the blood, and blood or eosinophil cells in sputum and mucus examinations are seen.

Gastroesophageal reflux and chronic cough

Reflux is responsible for about a quarter of cough causes. It is caused by micro-aspiration of esophageal contents into the larynx and airways. Reflux symptoms do not occur in more than half of these patients. Coughing after meals is typical. It may be accompanied by burning behind the chest wall, dysphagia, dysphonia, hoarseness, bitter taste in the mouth, and gastric acid reflux from the mouth.

In reflux patients, first of all, raising the headboard, losing weight, having a low-fat diet, avoiding substances such as cigarettes and caffeine that increase acid secretion can provide conservative treatment. In cases where conservative treatment is not sufficient, drug therapy can be applied. Sometimes, these patients may also have conditions that require surgical treatment.

ACE inhibitors and chronic cough

While cough can be seen in nearly one third of patients using ACE inhibitors, 3% of the total of chronic cough cases are caused by the use of ACE inhibitors. It is more common in women. This situation, which is not dependent on the drug dose, may occur hours after the drug intake. It resolves within an average of 4 weeks with discontinuation of the drug.

In patients with chronic cough, 60% of the patients have many diseases together rather than a single cause.

The most common causes of chronic cough in children are:

  • Postnasal drip syndrome
  • Recurrent viral bronchitis
  • Post infectious cough
  • Pertussis-like disease
  • Cough variant asthma
  • Upper airway cough syndrome
  • Psychogenic cough
  • Chronic suppurative lung diseases
    • Cystic fibrosis
    • Immunodeficiency
    • Primary ciliary dyskinesia
    • Recurrent pulmonary aspiration
    • Foreign body aspiration
    • Chronic bronchitis
  • Airway lesions
    • Compression due to tuberculosis
    • Congenital anomalies (Tracheoesophageal fistula)

Postnasal drip syndrome in children (Upper airway cough syndrome)

The most common cause of chronic cough in childhood is postnasal drip syndrome. It is also referred to as upper airway cough syndrome. It is formed by mechanical stimulation of cough receptors in the mouth and throat. The cough reflex is stimulated more easily in these patients. These patients usually have some accompanying conditions. These:

  • Nonallergic rhinitis
  • Allergic rhinitis
  • postinfectious rhinitis
  • Vasomotor rhinitis
  • Medicines
  • Environmental irritants
  • Adenoiditis

In these children, there may be complaints such as a feeling of discharge in the throat, runny nose, nasal congestion, the need for constant throat clearing, snoring and wheezing.

Postinfectious cough in children

Recurrent viral infections are the most common cause of cough, especially in preschool children. Healthy children without a history of asthma may have a cough lasting longer than three weeks following a sudden onset of upper respiratory tract infection. Wheezing is not usually seen. It is more common in autumn and winter. It mostly occurs after viral infections. The cough is sputumless and can last 8-12 weeks. It then disappears on its own.

Patients with chronic cough symptoms should be evaluated in the hospital environment and their treatment should be arranged for the underlying cause. Because, although rare, it can be a symptom of serious diseases.

Rare but serious health conditions that show no signs of coughing:

  • Emphysema
  • Thoracic wall perforation
  • Pleural fibrosis

Other rare causes of chronic cough:

  • Bronchogenic carcinoma
  • Benign endobronchial tumors
  • Tuberculosis
  • Sarcoidosis
  • fungal diseases
  • Lung abscess

Bronchogenic carcinoma is more common in smokers for years. Along with coughing, there is also hemoptysis and weight loss. Asbestos exposure can also trigger this disease.

Bronchial adenoma is a condition that causes chronic cough with wheezing complaint, does not have systemic symptoms and can cause hemoptysis from time to time.

Chronic granulomatous disease causes a chronic cough that occurs frequently. The only symptom may be a cough. Sometimes there may be increased sputum production, night sweats, weight loss and hemoptysis.

Lung abscess creates a picture of bad odor, foul-smelling sputum and fever in the mouth after recent dental or oral surgery or pneumonia. Often these patients also have excessive alcohol use.