Different types of Cough

Learning Objectives

By the end of the lecture, the student should be able to:

  1. Describe Cough.
  2. Discuss the causes of Cough.
  3. Discuss the characteristics of cough originating at various levels of Respiratory Tract.
  4. Tell us the various types of Cough.

Lecture Outline

Cough:

A cough is adefensive reflex of the body that functions to keep the airways clear of irritating or obstructing substances so that breathing and the intake of oxygen is effective.

It is the most frequent symptom of respiratory disease.

Causes of Cough:

It is caused by stimulation of sensory nerves in the mucosa of pharynx, larynx, trachea and bronchi.

Classificationof Cough:

A cough can be classified by its duration, character, quality, and timing.

The duration can be either acute (of sudden onset) if it is present less than three weeks, subacute if it is present between three and eight weeks, and chronic when lasting longer than eight weeks

A cough can be dry or productive, depending on whether sputum is coughed up. It may occur only at night, during both night and day, or just during the day.

  1. Acute Cough:

The cause of the acute cough is usually determined by the person’s history and physical exam.

  • If cough is present less than three weeks.
  • Most commonly relates to
  • Viral – induced lower respiratory tract infections.
  • Post-nasal drip resulting from rhinitis or sinusitis.
  • Throat - clearingsecondary to laryngitis or pharyngitis.

Post-nasal drip: Mucous accumulation in the back of the nose and throat leading to or giving the sensation of mucus dripping downward from the back of the nose.

  1. Subacute Cough:if it is present between three and eight weeks.

The most common causes are:

  • Post infectious Cough.
  • Acute Sinusitis.
  • Asthma.
  1. Chronic Cough:
  • When cough lasting longer than eight weeks.
  • Patients with chronic cough often represent more of a diagnostic challenge like individuals with a normal examination, chest radiograph and lung function tests.
  • Most cough can be explained by
  • Post-nasal drip secondary to nasal or sinus disease,
  • Asthma , where cough may be the principal or exclusive clinical manifestation Or
  • Gastro-oesophageal reflux(mayrequire ambulatory pH monitoring or a prolonged trial of antireflux therapy to diagnose.
  1. Dry Cough:
  • Cough is dry i.e. there is no phlegm⁺ when a person coughs.
  • The throat feels itchy and scratchy due to the dryness.
  • The throat pains due to excessive coughing.
  • It is difficult to eat due to excessive coughing.
  • Fever may accompany the cough but it is not a necessary symptom.

The dry, hacking cough is caused by:

  • a virus infection,
  • cold or dry air, or
  • Air pollutants such as cigarette smoke, smog and dust. This sometimes feels like a tickle at the back of your throat.

⁺Phlegm is a sticky material from your mucous membranes in your respiratory system. When you have a cold it might be yellowish brown. If there's an infection, it might be greenish brown. Normal phlegm is usually clear.

  1. Productive Cough:
  • Productive cough are coughs that produce phlegm, in contrast to dry coughs.
  • Usually treated with expectorants that loosen mucus from the respiratory tract.
  • Productive cough is associated with tuberculosis, bacterial pneumonia, and bronchitis .

The loose productive cough is a sign of chest congestion or infection due to colds or flu. It clears the lungs and air passages of excess mucus.

Characteristics of cough originating at various levels of Respiratory Tract:

Origin / Causes / Characteristics
Pharynx / Post nasal drip / Usually Persistent.
Larynx / Laryngitis, tumor, whooping cough, croup / Harsh, barking, painful, persistent, often associated with strider.
Trachea / Tracheitis / Painful
Bronchi / Acute Bronchitis and COPD
Asthma.
Bronchial Carcinoma / Dry or Productive, , worse in mornings.
Dry or productive, worse at night.
Persistent often with haemoptysis.
Lung Parenchyma / Tuberculosis
Pneumonia
Bronchiectasis
Pulmonary edema
Interstitial Fibrosis / Productive, often with haemoptysis.
Initially Dry, Productive later.
Productive
Often at night ( may be productive)
Dry, irritant and distressing.

Treatment:

Treatment of a cough generally involves treating the condition causing it.

  • An acute infection such as pneumonia may require antibiotics,
  • An asthma-induced cough may be treated with the use of bronchodilators, or
  • An antihistamine may be administered in the case of an allergy.
  • Physicians prefer not to suppress a productive cough, since it aids the body in clearing respiratory system of infective agents and irritants.
  • Cough medicines may be if the cough is not productive, as is the case with most coughs associated with colds or flu.
  • The two types of drugs used to treat coughs are antitussives and expectorants.

REFERENCES:

  • Davidson’s Priciples and Practice of Medicine. 20th Edition.
  • About.com.
  • Answers.com