What causes hemorrhoids? what are the best non-surgical ways of managing/dealing with them?

Straining : usually straining or any increase pressure in the lower abdomen that will cause the vein to dilate and any abdominal condition that will cause increase venous pressure like portal hypertension.since the most common reason is straining ,avoiding that by keeping the bowel soft and regular by hydration ,eating more fibers and fruits and vegetables.non surgical way to eliminate symptoms only