Covering your mouth when coughing is a basic public health practice known as respiratory hygiene. This deliberate action helps to contain infectious particles, preventing them from contaminating shared air and surfaces. The practice limits the transmission of various respiratory pathogens, including the common cold and influenza. Understanding proper containment methods protects both your own health and the health of those around you.
The Science of Respiratory Droplet Spread
An uncovered cough is an explosive event that forcefully expels thousands of germ-carrying particles from the body. A single cough can eject approximately 3,000 droplets at high speeds, creating a turbulent jet of air. These particles are categorized by size, which determines their behavior and travel distance. Larger respiratory droplets (greater than 5 to 10 micrometers) fall quickly due to gravity, settling onto surfaces or people within six to eight feet. Smaller aerosols (less than 5 micrometers) remain suspended in the air for minutes or hours, potentially traveling greater distances. Covering the mouth immediately disrupts this forceful expulsion, reducing the velocity and distance the pathogen plume can travel.
Proper Techniques for Cough Hygiene
Using a Tissue
The most effective method for containment involves using a disposable barrier, such as a tissue, to cover the mouth and nose completely. This action traps the majority of the expelled droplets. The used tissue must then be immediately thrown into a trash receptacle.
Using the Elbow
If a tissue is not available, the recommended alternative is to cough into the upper sleeve or the crook of the elbow. This method prevents germs from landing directly onto the hands, which are frequently used to touch surfaces. However, the elbow method is less effective than a tissue because droplets can still escape.
Avoiding the Hand
Coughing directly into the hand is the least effective technique and is strongly discouraged. A hand covered in respiratory fluid can quickly contaminate any object it touches, such as doorknobs or handrails. This rapid contamination creates a surface transmission pathway.
Preventing Surface Contamination
Contaminated hands act as a primary vector for germ transmission onto shared surfaces. Proper hand hygiene must follow immediately after any cough, regardless of the covering method used. Washing hands with soap and water is the preferred method for removing pathogens. The handwashing process should involve scrubbing all surfaces of the hands, including the backs, between the fingers, and under the nails, for a minimum of 20 seconds. If soap and water are not accessible, an alcohol-based hand sanitizer can be used as an alternative. The sanitizer must contain at least 60% alcohol to effectively denature the proteins of viruses and bacteria. When using sanitizer, apply enough product to cover all surfaces of the hands and rub them together until they are completely dry.