Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the symptoms of Renal Artery Stenosis ?
    ### Response:
    In many cases, RAS has no symptoms until it becomes severe.
                
The signs of RAS are usually either high blood pressure or decreased kidney function, or both, but RAS is often overlooked as a cause of high blood pressure. RAS should be considered as a cause of high blood pressure in people who

    