Eating too much or too fast, fizzy drinks and getting very excited can start hiccups. Hiccups most often come from a stretched, full stomach. Hiccups are a reflex: the diaphragm contracts suddenly, which causes a sudden intake of breath that is cut off when the glottis closes. People try many folk remedies. Britannica says they aim to interrupt the rhythm of the diaphragm spasms, and holding your breath for as long as possible is the most common one. These are things people try, not proven cures. If hiccups last longer than 48 hours (two days), a grown-up should take the person to a doctor.

Dust, pollen, spicy food and strong feelings can set off a sneeze, which starts when something irritates the lining of the nose or throat and sensory nerves send the alarm. A sneeze is a team effort: nerves in the nose send a message to the brainstem, and many muscles then work together to push the air out. In a recent research review, the airflow in a sneeze was reported to reach nearly 100 kilometers per hour (about 60 miles per hour), and a sneeze can send up to 40,000 tiny droplets out of the nose and mouth.

People tend to yawn most when they have just woken up or when they are tired, and people often yawn when they are bored. People also tend to yawn when they are nervous or before an important event. Yawns are catching: yawning can make a person yawn even if they only hear or think about a yawn. We are much more likely to catch a yawn from a close loved one than from a stranger, and adults yawn about eight to nine times a day on average.

Sneezes and coughs can spread germs, such as the germs that cause a cold. When you sneeze, cover your nose and mouth with a tissue, or sneeze into your elbow if you have no tissue, then wash your hands, because washing your hands with soap and water after you sneeze helps stop germs from spreading. Cleveland Clinic says you should never try to hold in a sneeze, because holding one in can be bad for your health. You may have heard that your eyes will pop out if you sneeze with them open. They will not: closing your eyes is an automatic reflex, and it is possible to keep them open, but it takes a lot of concentration. Your heart does not stop when you sneeze, either.

Some people sneeze when they step from a dim place into bright light, which is called the photic sneeze reflex. Photic sneezing runs in families. As of November 2026, estimates of how many people sneeze in bright light vary: about 25% in a 2025 research paper, one in three at Cleveland Clinic, and 10 to 30 percent in a PBS report. Scientists are not sure how light makes people sneeze. The most popular theory is that signals cross between the optic nerve and the trigeminal nerve, which senses facial feelings like an itchy nose.

Words to know

• reflex: automatic body action
• glottis: throat gap
• brainstem: brain base
• photic: about light
• droplets: tiny drops