Hiccups, medically known as singultus, are involuntary contractions of the diaphragm followed by the abrupt closure of the vocal cords, resulting in the characteristic "hic" sound12. This reflex involves a complex arc including afferent nerves like the phrenic and vagus nerves, central neurological pathways in the brain stem, and efferent nerves that signal the muscles to contract3. Hiccups typically occur in cycles of 4 to 60 per minute and often involve the left hemidiaphragm more than the right4. While usually harmless and self-resolving, persistent hiccups lasting more than 48 hours may indicate underlying medical conditions and warrant medical attention24. Interestingly, hiccups can occur in adults, children, infants, and even in utero, where they may play a role in respiratory muscle training4.

Hiccups can be triggered by a variety of factors related to diet, emotions, physical conditions, and underlying medical issues. Here are some common causes of hiccups:

• Eating too quickly or overeating12

• Consuming spicy foods12

• Drinking carbonated beverages12

• Swallowing air while chewing gum or smoking3

• Sudden changes in temperature4

• Stress, excitement, or emotional distress24

• Drinking alcohol23

• Certain medications, including steroids and benzodiazepines45

• Medical conditions such as gastroesophageal reflux disease (GERD), brain tumors, or infections45

• Abdominal surgery or procedures involving the diaphragm5

For persistent hiccups lasting more than 48 hours, it's important to consult a healthcare provider as this may indicate an underlying medical condition requiring treatment.45

Here are some of the most commonly recommended remedies for hiccups, based on anecdotal evidence and potential physiological effects:

1. Hold your breath for 10-20 seconds

2. Breathe into a paper bag

3. Drink a glass of cold water quickly

4. Swallow a teaspoon of granulated sugar

5. Bite on a lemon slice or taste vinegar

6. Gently pull on your tongue

7. Gargle with ice water

8. Sip water from the opposite side of a glass

9. Hug your knees to your chest and lean forward

These remedies aim to interrupt the hiccup reflex by stimulating the vagus nerve, altering breathing patterns, or causing a mild sensory distraction. While not scientifically proven, many people find them helpful for stopping hiccups123. If hiccups persist for more than 48 hours, consult a doctor as this may indicate an underlying condition requiring medical attention45.

The diaphragm plays a central role in the hiccup reflex. Hiccups occur when the diaphragm involuntarily contracts, causing a sudden inhalation of air. This is immediately followed by the closure of the vocal cords, producing the characteristic "hic" sound12. The diaphragm, a dome-shaped muscle separating the chest from the abdomen, is primarily responsible for breathing. During a hiccup, irritation or stimulation of the phrenic nerve, which controls the diaphragm, can trigger these sudden contractions23. Interestingly, hiccups often involve only the left side of the diaphragm2. The rapid contraction of the diaphragm, combined with the closure of the glottis, creates a sharp reduction in intra-thoracic pressure, which may serve an evolutionary purpose in removing swallowed air from the stomach, particularly in young mammals during feeding2.