5% of patients with type B AD, the mortality rate is higher at ≤33.3% (9).The reasons for the absence of pain in patients with AD are unknown, but according to reports, there are several possible reasons: i) The hematoma dilates into the aortic lumen, lateral pressure is low for the outer membrane with plexus distribution and there is no pain caused by the outer membrane protruding; ii) the dissection progresses slowly, and chronic stretch stimu- lation may increase the pain threshold (7); iii) the severe spinal cord ischemia that has occurred makes the viscera, spinal cord and thalamus lose their ability to sense pain, thus the ability of the patient to sense pain is reduced (10); iv) the gap between the false cavity and the true cavity is large and numerous, the pres- sure in the false cavity is low and no obvious pain is caused. A previous stud has also shown that patients with AD who have a history of Marfan syndrome may also present with painless symptoms (11).There were a number of deficiencies in the diagnosis and treatment process of this case, such as the pre-existing diagnosis of ileus, ignoring hypertension as the main cause, failing to compare the blood pressure of both upper limbs and failing to pay attention to vascular murmurs due to insufficient physical examination. Painless AD is rare in the clinic. The present case report suggested that there was an insufficient blood supply, mainly due to the tear of the intima and media of the vessel, and blood flowing into the interlayer from its own tubular channels, resulting in hemodynamic changes. An insufficient distal blood supply may lead to reduced or absent arterial pulsation, ischemia of the head may lead to lethargy, apathy and syncope, and ischemia of the spinal cord may lead to limb weakness and paraplegia (12,13). When dissection occurs in the aortic arch, there is a significant difference in the blood supply between the brachiocephalic trunk and the left subclavian artery, which may result in a significant differ- ence in blood pressure between the left and right upper limbs. The same thing can happen in other parts of the body to cause huge differences between the upper and lower limbs (14). As the torn intima forms a ‘reservoir sac’, this portion of blood may fall back during diastole to cause aortic valve murmurs (12). Therefore, a new aortic murmur is also a high-risk sign for AD; however, it has been reported that 32% of patients with painless AD have no vascular murmur (15). Clinical attention to the physical examination can be lead to a more timely diag- nosis of painless AD. Fortunately, in the present study, the AD was incidentally found during abdominal CTA, which resulted in the correct diagnosis and treatment, and avoided adverse consequences. Therefore, physicians should be aware of this relatively rare presentation of painless type B AD.In conclusion, the clinical manifestations of typical AD are easy to recognize, but the hidden and complex clinical manifestations are easy to ignore or misdiagnose. The rate of missed diagnosis and misdiagnosis in patients with first painless AD is higher than that in patients with pain, and the mortality rate is higher. Therefore, clinicians should be alert to painless symptoms and subtle signs related to AD, and should pay enough attention to them.