The severity of gallbladder wall thickening of 0.4 cm cannot be generalized, and needs to be assessed in conjunction with the causative factors of gallbladder thickening, clinical symptoms, and physical condition. 1. The degree of thickening: the normal gallbladder is 0.1-0.2 centimeters, and 0.4 centimeters is not too serious in terms of thickness. 2. Clinical symptoms: 0.4 cm of thickening of the gallbladder wall is not serious if no clinical symptoms occur; if there is obvious abdominal pain, bloating, dyspepsia, etc., attention should be paid. 3. Accompanying symptoms: If the patient has more gallbladder stones, larger gallbladder stones, as well as solitary gallbladder polyps and other diseases that can cause obvious clinical manifestations, even a thickening of 0.4 cm is a more serious manifestation of the need to consider surgical treatment. In conclusion, if the symptoms of gallbladder thickening appear, you should go to the hospital in time for examination and treatment under the guidance of the doctor.