Chronic hiccups can be triggered by several factors, including medical conditions such as pneumonia, liver cancer, hepatitis and digestive disorders, according to WebMD. Pregnant women and individuals who undergo surgical procedures may also experience extended bouts of hiccups.
Chronic hiccups are often attributed to inflammation of the nerves that assist the muscles of the diaphragm, explains Mayo Clinic. Irritation of these nerves can be caused by throat soreness, neck cysts and tumors. Conditions that hinder the function of the central nervous system, such as strokes, encephalitis and multiple sclerosis, can also cause long-term hiccups.
Individuals with hiccups lasting longer than 48 hours should consult with a medical professional to determine and treat the underlying cause of the condition, explains Healthline. Treatments for constant hiccups with no apparent cause include anti-nausea medications, anti-seizure medications and muscle relaxants.