Larissa Stouffer of Melrose, Mass., usually sneezes not once, not twice, but three times. She sneezes as she gets into a car if it's sunny outside, but not when it's cloudy; her dad does the same thing. And as soon as she pops some mint chewing gum into her mouth, out comes an achoo.
Stouffer, 30, isn't the only one with a fickle nose. Many people sneeze at peculiar moments -- such as after exercise, plucking their eyebrows, in the sunshine, or after sex.
Here are the reasons why they sneeze at odd times, and why all of us sneeze in the first place.
11 Surprising Sneezing Facts
1. "Sneezes start in your nerves," says Neil Kao, MD, an allergy and asthma specialist at the Allergic Disease and Asthma Center in Greenville, S.C.
Everyone's nervous system is basically wired in the same way, Kao explains. But signals traveling along nerves can take slightly different paths to and from the brain, resulting in different sneeze scenarios from person to person.
"It's a nerve transmission that tells your brain something is in your nose that needs to come out," Kao tells WebMD.
2. Sneezing helps keep your body safe. "Sneezing is an important part of the immune process, helping to keep us healthy and sniffle-free" Kao says.
Sneezes protect your body by clearing the nose of bacteria and viruses, Kao explains. When something enters your nose or you encounter a trigger that sets off your "sneeze center" in your brain, located in the lower brain stem, signals are rapidly sent to tightly close your throat, eyes, and mouth. Next, your chest muscles vigorously contract, and then your throat muscles quickly relax. As result, air -- along with saliva and mucus -- is forced out of your mouth and nose. Voila, you've sneezed.
3. Sneezes are speedy. "Sneezes travel at about 100 miles per hour," says Patti Wood, author of Success Signals: Understanding Body Language. She adds that a single sneeze can send 100,000 germs into the air.
4. Plucking your eyebrows may make you sneeze. Plucking may set off a nerve in your face that supplies your nasal passages. As a result, you sneeze.
5. You don't sneeze in your sleep. When you sleep, so do your sneezing nerves -- which means you usually don't sneeze when you doze.
6. Your workout may make you sneeze. "Exercise can make you sneeze," Kao says. "You hyperventilate when you're over-exerted, and as a result, your nose and mouth start to dry up. So your nose reacts by starting to drip, making you sneeze."
7. The longest sneezing spree: 978 days, a record set by Donna Griffiths of Worcestershire, England, according to background information on the Library of Congress' web site.
8. Sunshine may make you sneeze. "Bright sunlight causes one out of three people to sneeze," Wood says. "The light sneezers are called 'photics,' from the Greek meaning ‘of light.' And in fact, light sensitivity is an inherited trait -- just one more thing we can blame on our parents."
9. Sex can be a sneezing trigger. Have sex, must sneeze? It happens more often than you might think. Researchers believe that the stimulation of the parasympathetic nervous system fires off signals in some people to not only enjoy the act of sex, but to sneeze when it's over.
10. The sneeziest animal: the iguana. Iguanas sneeze more often and more productively than any other animal, according to Wood's research. Sneezing is how they rid their bodies of certain salts that are the normal byproduct of their digestive process, Woods says.
11. How do you stop a sneeze? While it's not foolproof, "Try breathing through your mouth and pinching the end of your nose," Kao says.
Strange sneezing facts aside, there are some beliefs about sneezing that just aren't true.
For instance, it's not true that your heart stops when you sneeze. When your chest contracts because of a sneeze, your blood flow is momentarily constricted as well. As a result, the rhythm of your heart may change, but it definitely doesn't stop.
And your eyeballs cannot pop out of your head when you sneeze. Most people naturally close their eyes when they sneeze, but if they are able to keep them open, their eyes stay firmly planted in their heads where they belong. "While a person's blood pressure behind the eyes may increase slightly when he sneezes, it's not enough force to dislodge the eyeballs from the head," Kao says.
Wood has heard of other sneezing folklore, including the notion that if you sneeze, company is coming over, and if your cat sneezes, it's going to rain.
As for the blessing many people say after someone sneezes, Wood explains that the Greek word for sneeze is "pneuma," which means "soul or spirit."
"A post-sneeze blessing stems from the ancient belief that sneezing is a near-death experience, and that a blessing will prevent your soul or sneeze from escaping your body and will deter the devil from entering in," Wood says.