Blood clot. In some cases a clot can form in a hemorrhoid. This is referred to as a thrombosed hemorrhoid. Despite the fact that not hazardous, it might be incredibly painful and in some cases has to be drained. Before sclerotherapy, You could have an ultrasound exam of your legs https://www.sgvascularctr.com/varicose-vein-treatment-in-singapore-answers-to-your-most-common-questions/