My echocardiogram reports shows mildly dialated ra/rv and mild tr/ estd rvsp of 36mmhg, cause unknown, what may be the reason & what's are the the risks?

Not sure: Without knowing more about your medical history and habits, it would be hard to know the cause. Mild dilatation of the ra/rv can be due to several problems, including chronic lung disease, pulmonary hypertension, tricuspid valve disease, a defect (hole) in the atrial or ventricular septum of the heart, abnormal arterial blood flow to the heart muscle, and severe obesity being just a few.