Have you ever wondered why people say "God bless you" after a sneeze? The custom dates from ancient times, when people thought that a sneeze allowed the soul to escape. By quickly shouting "God bless you," the onlooker could persuade the soul to return and prevent evil spirits from rushing into the body.
Today, we know that a sneeze is actually a protective mechanism — it's the body's way of quickly expelling dust, pollen, or some other irritant that could harm the lungs. The nose acts as the front door to the respiratory system. A network of nerves lines the mucous membrane, making the nostrils highly sensitive to foreign objects or irritants. When these nerves sense the presence of an irritant, they send an instant signal to the respiratory center in the brain, which in turn signals the breathing muscles to inhale. The muscles then close the airways, and the air pressure in the lungs rises. When this pressure reaches a certain high point, the airways open with an explosive release that carries everything in its way up and out of the airways and nose. Studies have found that the air expelled during a sneeze may travel at an amazing 100 miles per hour, and spew out up to 5,000 droplets, which may be propelled up to 12 feet in a single sneeze. This is how many illnesses are spread.
Everyone sneezes from time to time. Most often, sneezing is due to inhaling an irritant. Frequent sneezing, especially when accompanied by other symptoms, may also herald the onset of an illness.
Causes of sneezing
The adenoids are fleshy clumps of lymph tissue situated just behind the nose and above the
soft palate at the roof of the mouth. They help protect the body from bacteria, viruses, or other potentially harmful organisms. After puberty, they usually begin to shrink. Sometimes, however, they become enlarged and obstruct breathing. Frequent sneezing, nasal speech, and difficulty breathing through the nose are the most common symptoms.
During an asthma attack, the tiny muscles that control the airways constrict or tighten (a reaction called bronchospasm), restricting the flow of air to and from the lungs. Fits of sneezing and coughing often herald the onset of an attack and serve as a warning to take medication to reverse the bronchospasm.
Not all colds follow the same pattern, but most start with sneezing accompanied by tearing eyes, a runny nose, and reduced senses of taste and smell. Sneezing helps spread colds from person to person — in fact, a single sneeze can scatter thousands of cold viruses into the air.
Flu, like the common cold, is caused by a virus. It has many of the same symptoms as a
Sneezing is a hallmark of the common cold and allergies.
cold, but the onset is more rapid and the illness is more debilitating. Early symptoms include sneezing, nasal congestion, a sore throat, muscle aches, and perhaps a fever.
Foreign objects in the nose
Young children often stuff foreign objects — beads, peas, wads of tissue or paper, etc. — into their noses. Frequent sneezing unaccompanied by other symptoms of a cold should prompt an inspection of the child's nose to make sure it is free of such objects.
Violent sneezing is the hallmark of hay fever, the seasonal allergy that affects mostly the nose and eyes. The sneezing is usually triggered by an allergic reaction to pollen, but animal dander, dust, feathers, perfume, and similar substances can also bring on an allergic response. In addition to frequent sneezing, most people with hay fever also suffer nasal congestion, itching, and tearing eyes.
Advice about sneezing
- To keep from passing a cold or flu to others, cover the nose and mouth when sneezing or coughing. If possible, stay home during the sneezing (contagious) stage.
- Frequent, violent sneezing may rupture a tiny blood vessel in the eye. The reddened eye may look alarming, but the blood will be reabsorbed in a few days, and it poses no danger. In rare cases, however, a violent sneeze can cause a detached retina, which requires prompt treatment.