Sudden pain in the back may have the following causes: first, heart disease, when the heart has angina or heart attack, the pain in the left back can appear radiologically, then the ultrasound, electrocardiography and angiography of the heart should be performed for early diagnosis and early treatment; second, gallbladder disease, when the gallbladder has cholecystitis or gallbladder stones, the pain in the right side of the back can appear reflexively. In this case, ultrasound and CT examination of the gallbladder should be performed for early diagnosis and early treatment; third, diseases of the pancreas, if the sudden pain is below the middle of the back, it may be caused by pancreatitis or malignant tumor of the pancreas, and CT and MRI examination of the pancreas and blood tests should be performed for early diagnosis and treatment; fourth, pleurisy, pleurisy can also lead to sudden pain in the back. Fourth, pleurisy can also lead to sudden pain in the back, and CT examination of the chest should be performed for early diagnosis.