Hiccups are involuntary contractions of the diaphragm, the muscle that separates the chest from the abdomen. When the diaphragm spasms, it causes a sudden intake of breath that is quickly stopped by the closure of the vocal cords, producing the characteristic "hic" sound. Hiccups can occur for various reasons, including eating too quickly, consuming carbonated beverages, or experiencing sudden changes in temperature. Most hiccups are harmless and resolve on their own within a few minutes. However, persistent hiccups lasting more than 48 hours may require medical attention, as they can indicate underlying health issues. Common remedies include holding one's breath, drinking water, or swallowing a teaspoon of sugar.