Cough

1 Cough Summary

A cough is a normal reflex action of the body to clear the throat and respiratory tract off foreign substances or irritants. A cough as a reflex action is infrequent or periodic, based on the presence of irritants in the tract.

But there are a number of causes that can trigger frequent bouts or episodes of coughing. A cough can be categorized as acute and chronic. A cough that is persistent for more than six to eight weeks is known as a chronic cough.

A cough that is present for less than three weeks is referred to as an acute cough. A cough that is persistent for three to eight weeks is known as a subacute cough.

Most bouts of a cough resolve on its own without any specific treatment or with simple home treatment. If it that does not improve within few weeks, then it may be an indication of a more serious condition.

Coughing results from irritation of the nerve endings in the airways. Irritants like smoke, pollen, and some medical conditions may result in a cough.

Some common causes of a cough are: 

  • Chronic bronchitis
  • Asthma
  • Allergy
  • Chronic obstructive pulmonary disease (COPD)
  • Gastroesophageal disease (GERD)
  • Smoking
  • Disorders of throat
  • Certain medications

An acute cough may be caused by cold or upper respiratory tract infections like flu, pneumonia, and whooping cough. A subacute cough may remain even after an infection is resolved.

A chronic cough may be caused by asthma, GERD or upper airway cough syndrome. Certain symptoms when present along with a cough, indicate a serious problem.

This includes fever, chest pain, headaches, drowsiness, and confusion. Coughing up blood and breathlessness also require immediate medical attention.

A cough is treated based on the underlying cause of the symptom. In most of the cases, simple self-care may be of help in treating the condition.

Using cough drops, avoiding irritants, having plenty of water, adding honey and ginger to drinks, and gargling with hot water are some of the simple home treatments that will be of help in alleviating cough.

Physical examination, medical history, and symptoms are the common measures used to diagnose the underlying cause of a cough. Antibiotics are used to treat a cough due to bacteria.

Expectorant cough syrups and cough suppressants are commonly used to reduce bouts of a cough. Additional tests and investigations are recommended when the cause cannot be diagnosed with physical examination or to confirm the cause of a cough.

Blood tests, skin tests, imaging studies, and echocardiogram are all used in the confirmatory diagnosis of the cause.

In most cases cough resolves on its own without any specific treatment. Those caused by viral infections may be short lived and goes away within a week or two. In some rare cases, the cough may lead to complications like dizziness, tiredness, headache and fractured ribs.

The complications may resolve once cough of the underlying condition is treated. Most forms of a cough can be prevented by lifestyle modifications.

This includes quitting smoking, having balanced and healthy diet, and avoiding contact with people who have contagious diseases. A smoking-related cough tends to persist for a long duration when compared to others.

2 Causes

A cough is categorized into acute and chronic. An acute cough has a sudden onset and lasts for about 2-3 weeks. A chronic cough develops gradually and lasts for more than 6-8 weeks. Causes of an acute cough are divided into infectious and non-infectious causes.

Infectious causes of an acute cough include: 

  • Upper respiratory tract infections caused by a virus like common cold. This is one of the most common causes of a cough. A cough caused by flu infection may take more time to resolve.
  • Sinus infections
  • Acute bronchitis
  • Whooping cough
  • Pneumonia

A whooping cough is a contagious bacterial infection caused by Bordetella pertussis. It causes violent bouts of a cough and in small children this may be potentially fatal.

Non-infectious causes of an acute cough include flare-up of chronic diseases like chronic bronchitis, emphysema, asthma and allergies. Coughing caused by asthma involve wheezing and is easy to identify.

Causes of a chronic cough are categorized into environmental irritants, lung conditions, conditions of respiratory passages, conditions of the chest cavity and digestive causes.

Irritants – long-term exposure of lungs and respiratory passages cause a chronic cough. One such irritant is cigarette smoke and this is the second most common cause of a cough. Dust, pollen, particulate matter, pet dander, chemicals, and pollutants are irritants that can lead to a chronic cough.

Lung conditions – many conditions that affect lungs may lead to a chronic cough. Asthma, emphysema, and chronic bronchitis are some of the common causes of this type of a cough.

Some less common causes of a cough include cancer, sarcoidosis, lung tissue disease, congestive heart failure, and fluid retention in lungs. Bacterial pneumonia may also cause a chronic cough with fatigue, weakness, sputum and breathlessness as the associated symptoms.

Conditions of respiratory tract – respiratory passage connect the lungs to the outer atmosphere. Chronic infections of sinus, chronic post-nasal drip, outer ear diseases and throat infections are implicated in the development of a chronic cough.

People with sinus infections may often complain of a tickling sensation in the throat. They often tend to clear their throat because of discomfort.

Diseases of chest cavity – disease of the chest cavity outside the lungs and respiratory passage may result in a chronic cough. This includes abnormal growth of lymph node, cancer, and enlargement of the aorta, the largest blood vessel of the body.

Gastroesophageal reflux disease (GERD) – GERD is one of the most common digestive cause of a chronic cough. This occurs when acid from the stomach moves into the esophagus causing irritation resulting in a reflex cough.

In some cases, GERD may be so severe that substances are inhaled into the lungs, damaging the tissues of the organ. In some cases, chronic cough is the only symptom of GERD.

Certain medications may also result in the development of a chronic cough. Angiotensin-converting enzyme (AE) inhibitors, used in the treatment of high blood pressure is also a cause of a chronic cough in many people.

Discontinuation of medication helps to relieve a cough. Damage to vocal cords is also implicated in the development of a chronic cough. A persisting cough should be evaluated by the doctor for the underlying cause of the condition.

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3 Diagnosis and Treatment

Diagnosis of the cause of a cough is based on symptoms and also on the basis of information on duration of a cough, accompanying symptoms, activities that worsen or improve a cough, and the time of day during which a cough worsens.

Medical history and physical examination also help in identifying the underlying cause of a cough. Some common questions, the responses to which help in diagnosis include other medical conditions, the presence of heartburn, any recent infections, exposure to smoke, air pollution and dust.

The cause of an acute cough is identified on the basis of symptoms, medical history and physical examination of the patient. X-rays are generally recommended for people with weakened immune system and also patients with abnormal lung sounds. This is particularly useful in elderly people in diagnosing the cause of a cough.

Diagnosis of a chronic cough is often based on physical examination and interview of the patient. Further diagnostic tests and investigations are based on the suspected cause of a cough. For example, the pH probe is often suggested for people with symptoms of GERD.

Some other common tests used in confirmatory diagnosis include analysis of mucus from nasal cavity and throat. This helps in the identification of the causative organism. A chest x-ray is helpful in diagnosing lung conditions like pneumonia.

Lung functions tests are recommended to diagnose asthma and other lung conditions. In this test, the amount of air that is inhaled and exhaled is measured. It gives an indication of how well oxygen is delivered to different organs. Sinus infection is assessed using x-rays in some cases.

Treatment of a cough depends on the underlying condition. Thus in an acute cough, treatment focuses on reducing cough and treating the underlying condition. Over-the-counter and prescription medications are used in providing symptomatic relief for a cough.

Narcotic medications are suggested for a cough that affects sleep. Antibiotics are recommended for controlling bacterial infections that cause an acute cough.

Viral diseases that cause a cough will be treated symptomatically. Hospitalization is required for elderly people, people with weakened immune system, and patients with severe bacterial and viral infections.

A chronic cough caused by smoking, irritants, and allergies is controlled by preventing exposure to the causative substance. Treatment for lung diseases is usually multiple and long-term to alleviate the symptoms.

Improvement of the condition is often gradual and may take several days to weeks to note the same. Stopping the medication or reducing the dose of medication that causes a cough is one of the most important steps in reducing cough caused by medications.

Controlling GERD using medications help to alleviate a chronic cough. In addition to medications, it may also need dietary changes.

A cough can be avoided by simple preventive measures too, this includes: 

Quitting smoking – smoking is one of the most common causes of a chronic cough. Quitting smoking reduces the risk of common cold and flu, two other causes of a cough.

Dietary changes – healthy diet rich in flavonoids and fiber reduces the chances of developing a chronic cough.

Keeping away from people who have contagious diseases reduces the risk of conditions that cause a cough. Keeping the existing medical conditions, like asthma and GERD, under control helps to prevent chances of a cough. Once managed, cough reduces considerably.

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