The first hand may be the internal hemorrhoids in squatting or abdominal pressure increased hemorrhoid rupture bleeding, on the other hand may be the existence of hemorrhoids erosion, ulcers, in the urine around the muscle contraction extrusion lead to bleeding. 1. internal hemorrhoids: internal hemorrhoids are hemorrhoids that grow above the dentate line, the reason for their appearance is that the rectal venous plexus blood reflux is impeded, the long-term venous plexus is varicose, in the urine or abdominal pressure increases, the rectal venous plexus friction leads to rupture and bleeding. 2. erosion, ulceration: if in the case of hemorrhoids also combined with hemorrhoidal infection, erosion, ulceration, in the discharge of urine anal sphincter and the surrounding collateral muscle contraction, but also on the erosion, ulceration of hemorrhoids extrusion, so that the newborn capillary venous plexus and the granulation tissue rupture, intuitively see hemorrhoids bleed. Therefore, if bleeding hemorrhoids appear when urinating, you should go to the hospital in time for examination, to clarify the specific cause, and give reasonable treatment, so as not to aggravate the progress of the disease.