There are lots of home remedies to get rid of them — stand on your head, drink water, be startled — but no real reason why we get them. A new study, however, sheds light on hiccups, those annoying, involuntary contractions of the diaphragm muscle.
Researchers at University College London studied 13 newborns in a neonatal ward who had a bout of hiccups. The babies were preterm and full term, ranging from 30 to 42 weeks gestational age (equivalent), so their development could reflect what’s typical in the last trimester of pregnancy.
Hiccups begin in the womb at just nine weeks gestation, and preterm infants spend about 15 minutes a day hiccuping.
By attaching electrodes to the babies’ scalps and motion sensors to their torsos, researchers could monitor brain activity when a baby would hiccup.
“The reasons for why we hiccup are not entirely clear, but there may be a developmental reason,” given that fetuses and newborns hiccup so often, the study’s lead author, research associate Kimberley Whitehead.
According to the UCL report, researchers found that contractions of the infant’s diaphragm muscle from a hiccup evoked a pronounced response in the brain’s cortex — two large brainwaves followed by a third. That postnatal processing of multisensory inputs, the researchers said, is important to develop brain connections.
“The activity resulting from a hiccup may be helping the baby’s brain to learn how to monitor the breathing muscles so that eventually breathing can be voluntary controlled by moving the diaphragm up and down,” said Lorenzo Fabrizi, the study’s senior author.
“When we are born, the circuits which process body sensations are not fully developed, so the establishment of such networks is a crucial developmental milestone for newborns,” he continued.
That adults get the hiccups could just be a holdover from our infancy, Whitehead said.