why is blood pressure higher in legs than in the arms?
There could be several reasons for this. Systolic pressure in lower extremities is significantly higher than in the upper extremities in people with occlusion in the upper extremities vascular system. An example of that would be Takayasu and Buerger's diseases, a dissecting aneurysm or a high stroke volume - aortic insufficiency as in Hill's sign. In an aortic insufficiency the systolic pressure is significantly
higher in the legs than in the arms.
When the opposite happens and the systolic is lower in the legs than in the arms by 6mmHg or more, it can indicate an obstruction in the vascular tree - atherosclerosis.
Hopefully, your doctor will be able to determine what the problem is.