Hemorrhoids are caused by excessive dilation of the hemorrhoidal venous plexus in the tissue around the anus and rectum. Normally, these tissues help control the passage of stool. When these tissues become inflamed and swollen, they are called hemorrhoids. Hemorrhoids are caused by excessive dilation of the hemorrhoidal venous plexus in the tissue around the anus and rectum. Normally, these tissues help control the passage of stool. When these tissues become inflamed and swollen, they are called hemorrhoids. Hemorrhoids are caused by excessive dilation of the hemorrhoidal venous plexus in the tissue around the anus and rectum. Normally, these tissues help control the passage of stool. When these tissues become inflamed and swollen, they are called hemorrhoids. Hemorrhoids in pregnant women account for a high rate and cause several discomforts, affecting pregnant women