External hemorrhoids are swollen veins that form beneath the skin around the anal opening, similar to varicose veins. They commonly result from increased pressure on the veins in the lower rectum and anus, often due to straining during bowel movements or prolonged sitting. Because they are located in an area with a high density of pain-sensing nerves, external hemorrhoids are typically more noticeable and may cause discomfort compared to internal hemorrhoids.
The Typical Appearance and Texture
A non-thrombosed external hemorrhoid presents visually as a small lump or bulge directly at the anal verge. The color often matches the surrounding skin, appearing flesh-toned or slightly pinkish. If the tissue is irritated or inflamed, the color may shift to a reddish hue.
The texture is generally soft, pliable, and somewhat rubbery to the touch. These swollen cushions of vascular tissue have a smooth surface and are often round or oval in shape.
Size and Specific Location
External hemorrhoids are defined by their location beneath the anoderm—the skin-like covering just outside the anal opening. They are visible and palpable lumps situated at the anal verge, distinguishing them from internal hemorrhoids that form within the rectum.
The physical dimensions of an external hemorrhoid can fluctuate significantly based on the degree of swelling and irritation. They can range from the size of a small pea in a mild state to the dimensions of a grape or larger when severely inflamed. This variability means the lump can appear smaller and then swell noticeably, even over a short period.
Appearance of a Thrombosed External Hemorrhoid
A thrombosed external hemorrhoid occurs when a blood clot (thrombus) forms within the swollen vein. This internal clotting dramatically changes the lump’s appearance. The most notable visual feature is the color transformation, which becomes a dark blue, purple, or even blackish hue due to the clotted blood trapped beneath the skin.
The texture also changes, feeling hard and firm rather than soft. The increased pressure from the clot causes the hemorrhoid to appear significantly more swollen and inflamed, often resembling a taut, discolored marble. This alteration is frequently accompanied by acute pain, as the trapped clot creates intense pressure on the surrounding nerve tissue.
Visual Signs That Require Medical Consultation
While many external hemorrhoids resolve with conservative care, certain visual signs indicate the need for professional medical evaluation. Heavy or persistent rectal bleeding is concerning, particularly if the blood is dark or the volume is significant. Although hemorrhoids often cause bright red blood, dark, tarry stool suggests bleeding from higher up in the digestive tract.
Any visual evidence of infection, such as spreading redness, warmth, pus, or foul-smelling discharge, should prompt a consultation. Medical advice is also necessary if the hemorrhoid becomes black or appears visibly necrotic, or if a thrombosed lump does not improve within a few days. Rapid changes in size or shape, or symptoms like lightheadedness or dizziness, indicate potential excessive blood loss or a complication.