<P> The aorta is not always torn completely through; it may also tear some but not all layers of the arterial wall, sometimes forming a false aneurysm . A sub-intimal hemorrhage is the least serious type . </P> <P> Being the mildest form, it often does not weaken the wall of the aorta and may heal on its own . Usually, it occurs in the descending aorta . It was originally defined as a small intimal flap with less than one centimeter length and with little or no haematoma . It is 10 - 28% of aortic injuries . </P> <P> Symptoms are often unreliable, but include: </P> <Ul> <Li> Severe tearing chest pain (sometimes) </Li> <Li> cough </Li> <Li> dyspnea </Li> <Li> dysphagia </Li> <Li> back pain </Li> <Li> hoarseness </Li> <Li> High upper body blood pressure </Li> <Li> Low lower body blood pressure </Li> </Ul>

The most common site of deceleration injury in the chest is the