Is a Cough Contagious?

A cough itself is not contagious. A cough also can be a method of spreading a viral or bacterial infectious disease if the disease is transmitted by airborne droplets.

A cough is defined as the act of forcing air through your throat, often followed by a short loud noise. Coughing can be a reflexive action to keep respiratory passages free of irritating substances (such as dust, mucous, phlegm, nasal drainage, and foreign bodies). Consequently, a cough reflex can be a protective mechanism for the individual. There are many types of coughs including:

• Dry cough: a cough that doesn't produce mucus (also termed a non-productive cough)
• Wet cough: a cough that produces mucus or sputum (also termed a productive cough)
• Barking cough: a cough associated with viral illnesses and/or croup especially in young children usually (croup cough)
• Whooping cough: a cough associated with infection (pertussis); individuals (usually children) produce a whooping sound when they cough
• Stress cough: a reflexive, nonproductive cough that occurs when an individual is under stress
• Acute cough: a cough that has just begun or has been intermittent, often resulting within a week or so.
• Chronic cough: a cough that is persistent over time (more than 1 to 8 or more weeks); the timeframe is controversial as health-care professionals and researchers list a variety of time frames to define a chronic cough

A cough itself is not contagious. Of note, a cough can be a sign of something irritating, impeding, or blocking an airway. But a cough also can be a method of spreading a viral or bacterial infectious disease if the disease is transmitted by airborne droplets. Consequently, people are understandably concerned that coughing is "contagious". However, what is actually contagious is the infecting pathogen, not the cough itself. The transmitted infecting agent may produce the same symptoms, including a cough, in another individual.

Coughing can induce a gagging reflex that, in turn, can produce vomiting. This situation of coughing with vomiting occasionally occurs. Vomiting can be reflexive and is a means to remove irritating material from the body, specifically the contents of the stomach.

Knowing the type of cough can provide some insight into the underlying cause of the cough.

• In general, dry coughs and stress coughs are often caused by noninfectious irritants.
• Some chronic coughs are due to long-term mucus production and/or irritating agents like cigarette smoke.
• Other coughs are caused by allergies bothering underlying lung disease.
• Some, but not all, productive coughs are caused by infectious agents as are whooping cough and croup.
• Coughing up blood or blood mixed with sputum is best evaluated by a health-care professional to determine the underlying cause(s). This combination is usually considered a medical emergency.

The underlying cause of chronic coughs should be investigated by a doctor.

The answer to this question is tricky. Coughs are not contagious, but certain underlying diseases that produce a cough are contagious, and can be spread by droplets formed during coughing. Correspondingly, when the underlying disease process is no longer contagious, the cough no longer produces infectious droplets.

The key is that coughs are signs or symptoms of underlying problems, and the cough itself is not contagious.

Coughs associated with non-infectious causes (such as dust, chemical irritants and smoking), and are not spread from person-to-person.

Coughs due to infectious diseases may seem like they are contagious and spread to others by person-to-person contact. However, the cough itself may or may not occur in another person with the same infection. If the infection causes cough and other symptoms in another person then, it will seem as though the cough was "spread," but the actual spread of symptoms including cough would be due to the spread of the underlying infection, not the cough itself. So, microbes can be transmitted from one person to another by coughing to produce droplets that carry pass them on.

In many instances, short-term cough (less than seven days duration) usually requires no medical care. However, the following list of problems associated with a cough should be investigated by a health-care professional:

• a cough lasting at least a week without improving
• chills and/or nighttime coughing fits
• a fever and a cough that lasts at least three or more days
• a deep cough that produces a lot of mucus and/or bloody mucus

Emergency care should be sought if the coughing includes any one or more of the following:

• significant wheezing
• shortness of breath
• chest tightness
• coughing up and/or vomiting blood (possible signs of internal bleeding due to bleeding ulcers or other significant causes)

Coughs can be irritating no matter what type of cough they are. Consequently, people want them to either stop or be markedly reduced. There are many over-the-counter (OTC) drugs and home remedies that can suppress or stop cough, and usually are relatively safe to use to treat acute coughs.

However, individuals that are pregnant and other individuals that have high blood pressure should consult their health-care professional before using coughs treatments. Some treatments may not be advisable or safe.

Individuals that try OTC drugs and home remedies that provide no cough relief should contact their health-care professional to determine if there is an underlying cause that needs treatment before trying to diminish the symptoms of coughing.