Hiccups happen because of involuntary spasms in the diaphragm muscle that controls breathing. The spasms cause the vocal cords to close suddenly, producing the characteristic "hic" sound. Common causes of frequent hiccuping include eating too much or too quickly, drinking carbonated or alcoholic beverages, emotional stress or excitement, swallowing air, and sudden changes in temperature. Sometimes, hiccups can also be caused by irritation or damage to the nerves controlling the diaphragm, certain medical conditions, or side effects of medications. If hiccups last longer than 48 hours or are severe enough to interfere with eating, sleeping, or breathing, it is advised to see a healthcare provider as it could indicate an underlying medical issue such as nerve irritation, central nervous system disorders, metabolic problems, or other health conditions.