Blood clot. Often a clot can form inside a hemorrhoid. This is named a thrombosed hemorrhoid. Despite the fact that not harmful, it may be exceptionally painful and from time to time should be drained. The veins round the anus are likely to stretch stressed and will bulge or swell. https://www.sgvascularctr.com/varicose-vein-treatment-in-singapore-answers-to-your-most-common-questions/