Below is an instruction from Human. Write a response.
    ### Instruction:
    Who is at risk for Pulmonary Hypertension? ?
    ### Response:
    The exact number of people who have pulmonary hypertension (PH) isn't known.
                
Group 1 pulmonary arterial hypertension (PAH) without a known cause is rare. It affects women more often than men. People who have group 1 PAH tend to be overweight.
    