Coughs

Bronchitis Slideshow Asthma Myths Quiz Slideshow

• Coughs Overview
• Causes of Coughs
• Cough Symptoms
• When to Seek Medical Care
• Exams and Tests
• Cough Treatment
• Self-Care at Home
• Medical Treatment
• Next Steps
• Follow-up
• Prevention
• Outlook
• Synonyms and Keywords
• Authors and Editors

Coughs Overview

A cough is an action your body takes to get rid of substances that are irritating to your air passages, which carry the air you breathe in from the nose and mouth to the lungs. A cough occurs when special cells along the air passages get irritated and trigger a chain of events. The result? Air in your lungs is forced out under high pressure. You can choose to cough (a voluntary process), or your body may cough on its own (an involuntary process).

Causes of Coughs

The list of possible causes of cough is long and highly varied. Doctors classify coughs into 2 categories, acute and chronic. Many doctors define an acute cough as one that been present for less than 3 weeks. Chronic coughs are those present for more than 3 weeks.

• Acute coughs can be divided into infectious (caused by an infection) and noninfectious causes.

• Infectious causes of acute cough include viral upper respiratory infections (the common cold), sinus infections, pneumonia, and whooping cough.

• Noninfectious causes of cough include flare-ups of the following chronic conditions: chronic bronchitis, emphysema, asthma, and environmental allergies.

• The easiest way to simplify the causes of chronic cough is to divide them into their locations with respect to the lungs. The categories are environmental irritants, conditions within the lungs, conditions along the passages that transmit air from the lungs to the environment, conditions within the chest cavity but outside of the lungs, and digestive causes.

• Any environmental substance that irritates the air passages or the lungs is capable of producing a chronic cough with continued exposure. Cigarette smoke is the most common cause of chronic cough. Other cough-producing irritants include dusts, pollens, pet dander, particulate matter, industrial chemicals and pollution, cigar and pipe smoke, and low environmental humidity.

• Within the lungs both common and uncommon conditions cause chronic cough. Common causes include asthma, emphysema, and chronic bronchitis. Less common causes of lung-induced chronic cough include cancer, sarcoidosis, diseases of the lung tissue, and congestive heart failure with chronic fluid build-up in the lungs.

• The passages that connect the lungs to the external environment are known as the upper respiratory tract. Chronic sinus infections, chronic postnasal drip, diseases of the external ear, infections of the throat, and use of ACE inhibitors for high blood pressure have all been implicated in chronic cough.

• In addition to disease processes within the lung and air passages, diseases elsewhere within the chest cavity may also be responsible for chronic cough. Conditions within the chest known to cause chronic cough include cancer, unusual growth of a lymph node, and an abnormal enlargement of the aorta, which is the main blood vessel leaving the heart.

• An often-overlooked cause of the chronic cough is gastroesophageal reflux (GERD). GERD occurs when acid from the stomach travels up the esophagus. This abnormal condition can cause irritation of the esophagus and larynx resulting in the reflex production of a cough.