What Are Thrombosed Piles: In-Depth Overview Piles, also known as swollen rectal veins, are dilated veins in the anal-rectal area. When a blood clot forms inside one, it leads to a thrombosed pile—a debilitating condition requiring attention. Below, explore the signs, triggers, and solutions for thrombosed haemorrhoids. ### Definition of http://That subreddit doesn't exist