Hiccups are one of the most universal physiological phenomena and, paradoxically, most ignored by modern medicine. Present in virtually all mammals and detectable even in human fetuses from the second trimester of gestation, it is still the subject of scientific debate: what is it for? Why does it persist in human biology if it apparently serves no vital function?

Few things are as harmless and exasperating at the same time as hiccups. He appears at the worst possible moment - in a work meeting, during a romantic dinner, in the middle of a presentation - and disappears with the same arbitrariness with which he arrived. However, behind that everyday sound hides a physiological mechanism of surprising complexity.

Everything around hiccups is a mystery, but it is not of interest to talk about the causes, their neurological mechanisms and the most effective - and supported - methods to stop them.

The diaphragm as an involuntary protagonist

Hiccups, in medical terms called singulum, are the result of a sudden, involuntary contraction of the diaphragm, the dome-shaped muscle that separates the thorax from the abdomen and regulates breathing.

When the diaphragm contracts spasmodically, it causes a sudden inhalation of air that, when it collides with the vocal cords, which close suddenly, generates the characteristic sound that we all know.

This process occurs in just 35 milliseconds: the spasm of the diaphragm, the closure of the glottis and the resulting sound make up a very fast and perfectly synchronized cycle that the organism executes without the will having any role in it.

What does the mechanism trigger?

The most frequent causes of transient hiccups -the one that lasts minutes or hours- are closely linked to daily habits. Eating too fast or too much is one of the most common triggers, as the dilated stomach presses on the diaphragm from below.

Ingestion of carbonated beverages, alcohol, sudden temperature changes in the mouth or digestive tract, and intense emotions such as laughter or crying can also trigger the reflex.

The phrenic nerve, which innervates the diaphragm, and the vagus nerve, which runs through much of the thorax and abdomen, are the nerve highways involved. When any of them receives an irritating or erroneous signal - be it chemical, mechanical or emotional - the reflex arc is activated and the spasm occurs.

In more rare cases, when the hiccups last more than 48 hours, it can be a sign of a more serious underlying condition: chronic gastroesophageal reflux, central nervous system pathologies, tumors in the chest, kidney conditions or even side effects of certain medications. In this scenario, medical consultation is essential.

Popular remedies under the magnifying glass

Popular tradition has built an authentic catalogue of remedies against hiccups. Many of them, even if they seem absurd, have a physiological logic behind them.

Hold Breath - Raises CO₂ in blood, which can inhibit the reflex arc of the diaphragm.

Breathe into paper bag. Similar to the previous one, it increases the concentration of carbon dioxide, relaxing the diaphragm.

Drink water slowly. It stimulates the vagus nerve rhythmically and can interrupt the spasm.

Swallowing granulated sugar. Mild irritation of the esophagus can “reset” the abnormal nerve signal.

Valsalva Maneuver: Breathing out forcefully with the mouth and nose closed modifies the chest pressure and stimulates the vagus.

Bend your knees to your chest. Compresses the diaphragm from the outside, being able to interrupt the spasmodic pattern.

What explains hiccups?

The question that most intrigues researchers is not how hiccups work, but what they exist for. An evolutionary hypothesis posits that the reflex is a vestige of our aquatic ancestors: in amphibians, a similar mechanism closes the glottis to prevent water from entering the lungs by breathing through gills. In humans, that reflex would have persisted without a clear function, a kind of neurological appendage.

Another theory, more recent, suggests that hiccups could serve to expel the air trapped in the stomach of nursing babies, facilitating burping and allowing them to continue feeding. The fact that fetuses develop the hiccup reflex as early as week 9 of gestation, long before the lungs are formed, reinforces this idea.

Whatever its evolutionary origin, hiccups in their daily and brief form do not pose any danger. Most episodes resolve in less than ten minutes without any intervention.

You may also like:

· A nighttime pill for sleep apnea is coming: promising results in phase 3· It's not just a matter of genetics! Factors that make women live longer than men· What does your body need from the age of 50?