Hemorrhoids fall into two main types based on where they form: internal hemorrhoids, which develop inside the rectum, and external hemorrhoids, which form under the skin around the anus. A third category, thrombosed hemorrhoids, describes what happens when a blood clot forms inside either type. Understanding which kind you’re dealing with matters because the symptoms, pain levels, and treatment approaches differ significantly between them.
Internal vs. External: The Key Boundary
The dividing line between internal and external hemorrhoids is a physical landmark called the dentate line, a ring of tissue inside the anal canal where the intestinal lining meets regular skin. This boundary matters for one critical reason: the tissue above it (where internal hemorrhoids form) has almost no pain-sensing nerves, while the tissue below it (where external hemorrhoids form) is rich with them. That’s why internal hemorrhoids can bleed without hurting, while external hemorrhoids often cause sharp, noticeable pain.
Internal Hemorrhoids and Their Grades
Internal hemorrhoids sit inside the rectum, out of sight. Their hallmark symptom is painless bleeding, typically small amounts of bright red blood on toilet paper or in the bowl after a bowel movement. Because they form in tissue with minimal nerve endings, you often won’t feel them at all unless they’ve progressed.
Doctors classify internal hemorrhoids into four grades based on how far they’ve slipped from their original position:
- Grade I: The hemorrhoid stays entirely inside the rectum. It may bleed but doesn’t protrude.
- Grade II: It pushes out through the anal opening during a bowel movement but slides back in on its own afterward.
- Grade III: It protrudes during bowel movements or straining and won’t go back in unless you manually push it into place.
- Grade IV: It stays permanently outside the anus and can’t be pushed back in. At this stage, pain and irritation become much more likely.
Most people with grade I or II internal hemorrhoids respond well to conservative treatment: dietary fiber, more water, and over-the-counter remedies. When these measures don’t work, office-based procedures like rubber band ligation can be effective. Grade III and IV hemorrhoids, especially when combined with external hemorrhoids, are more likely to need surgical removal. According to the American Society of Colon and Rectal Surgeons, excisional surgery should typically be offered to patients with symptomatic grade III or IV hemorrhoids who haven’t improved with less invasive options.
External Hemorrhoids
External hemorrhoids form beneath the skin surrounding the anus, in tissue packed with nerve endings. They tend to cause itching, irritation, swelling, and outright pain, particularly during bowel movements or when sitting for long periods. They can also bleed, especially if irritated by wiping or straining.
You can often see or feel an external hemorrhoid as a small, tender lump near the anus. One common source of confusion is the difference between an active external hemorrhoid and an anal skin tag. Skin tags are soft, painless flaps of skin that sometimes form after a hemorrhoid heals. They don’t bleed or swell. An active hemorrhoid, by contrast, is swollen, often painful, and can bleed when irritated. Skin tags are harmless, though some people find them bothersome enough to have removed.
Thrombosed Hemorrhoids
A thrombosed hemorrhoid develops when a blood clot forms inside a hemorrhoid, most commonly an external one. The telltale sign is a firm, bluish-purple lump near the anus that can be extremely painful and tender. Other symptoms include pain when sitting, walking, or having a bowel movement, along with bleeding if the surface ruptures.
The pain from a thrombosed hemorrhoid is usually worst in the first 48 hours. After that, your body gradually reabsorbs the clot, and pain improves a little each day. Most thrombosed hemorrhoids resolve on their own within a few weeks. Warm sitz baths, ice packs, and over-the-counter pain relief can help during this window. If the pain remains severe after a few days, a healthcare provider can drain the clot through a quick in-office procedure, which provides near-immediate relief.
Mixed (Combined) Hemorrhoids
Some people develop both internal and external hemorrhoids at the same time. These are sometimes called mixed or combined hemorrhoids. The combination can be particularly frustrating because you may experience bleeding from the internal component and pain from the external one simultaneously. Combined hemorrhoids that don’t respond to conservative measures are more likely to require surgical treatment than either type alone.
How Hemorrhoids Are Diagnosed
External hemorrhoids and thrombosed hemorrhoids are usually diagnosed through a simple visual and physical exam. Your doctor will check the area around the anus for lumps, swelling, skin tags, and signs of blood clots.
Internal hemorrhoids require a bit more investigation since they aren’t visible from the outside. A digital rectal exam, where your doctor inserts a gloved finger into the rectum, can check for tenderness, blood, and internal masses. For a clearer picture, your doctor may use an anoscope, a short, lighted tube that allows a direct view of the lining of the anus and lower rectum. Internal hemorrhoids are also sometimes spotted during colonoscopies or sigmoidoscopies performed for other reasons.
These procedures aren’t just about confirming hemorrhoids. They also help rule out other causes of rectal bleeding, including anal fissures (small tears in the anal lining) and more serious conditions. Bright red blood on toilet paper is a classic hemorrhoid symptom, but it’s worth getting checked if it’s new, persistent, or accompanied by changes in bowel habits.
What Affects Which Type You Get
The underlying cause is the same for all types: increased pressure on the veins in and around the anus. What differs is where that pressure takes its toll. Common contributing factors include chronic straining during bowel movements, sitting on the toilet for extended periods, a low-fiber diet that leads to hard stools, pregnancy (which increases pelvic pressure), obesity, and heavy lifting. Age plays a role too. The tissues supporting the veins in the rectum and anus weaken over time, which is why hemorrhoids become more common after age 50.
You can’t always control which type develops, but the preventive strategies are the same across the board: eat enough fiber (25 to 30 grams a day), stay hydrated, avoid prolonged sitting on the toilet, and don’t strain or hold your breath during bowel movements. These steps won’t eliminate hemorrhoids that already exist, but they can slow progression and reduce flare-ups.