An internal hemorrhoid is a swollen cushion of blood vessels inside the lower rectum, positioned above a boundary called the dentate line. Everyone has these vascular cushions. They only become a problem when they enlarge, bleed, or slip out of place. About 1 in 20 Americans deal with symptomatic hemorrhoids, and roughly half of adults over 50 have them.
How Internal Hemorrhoids Differ From External Ones
The anal canal has two distinct networks of blood vessels separated by the dentate line, a ring of tissue about two inches inside the opening. Internal hemorrhoids form above this line, where the tissue is lined with a type of mucosa that has very few pain-sensing nerves. That’s why internal hemorrhoids are typically painless, even when they bleed. External hemorrhoids, by contrast, develop below the dentate line under skin rich in nerve endings, which is why they tend to hurt.
The normal internal hemorrhoidal tissue consists of three soft cushions arranged in predictable positions around the anal canal. These cushions are spongy masses filled with a dense network of tiny blood vessels that allow blood to flow directly from small arteries into small veins through connections called sinusoids. This spongy tissue helps with fine control of continence. Problems start when these cushions swell, the supporting connective tissue weakens, and the cushions begin to slide downward.
Common Symptoms
The hallmark symptom is painless rectal bleeding. You might notice small amounts of bright red blood on toilet paper or in the bowl after a bowel movement. Because the tissue above the dentate line lacks the pain receptors found in skin, many people have internal hemorrhoids without knowing it.
As internal hemorrhoids enlarge, they can prolapse, meaning they push through the anal opening during a bowel movement. A prolapsed hemorrhoid can cause a feeling of fullness, mucus discharge, itching, and irritation. Pain typically only enters the picture once a hemorrhoid has prolapsed far enough to become trapped or irritated by the surrounding skin.
Grades of Internal Hemorrhoids
Doctors classify internal hemorrhoids into four grades based on how much they prolapse:
- Grade I: The cushions are enlarged and may bleed, but they don’t prolapse outside the anal canal.
- Grade II: They prolapse during straining but slide back inside on their own.
- Grade III: They prolapse and need to be pushed back in manually.
- Grade IV: They remain prolapsed outside the anal canal and cannot be pushed back in.
Grade determines treatment. Lower grades usually respond well to lifestyle changes and office procedures, while grade III and IV hemorrhoids more often require intervention.
What Causes Them to Develop
Anything that increases pressure in the lower rectum or weakens the connective tissue holding those vascular cushions in place can contribute. Chronic straining during bowel movements is the most common trigger, often driven by constipation or prolonged sitting on the toilet. Pregnancy increases abdominal pressure and blood volume, making hemorrhoids especially common in the third trimester. Aging gradually loosens the supportive tissue, which is why prevalence climbs after 50. Obesity, heavy lifting, and a low-fiber diet also raise risk.
How Internal Hemorrhoids Are Diagnosed
Because internal hemorrhoids sit inside the rectum, you usually can’t see or feel them yourself. A standard digital rectal exam often isn’t enough to identify them reliably either. The preferred tool is an anoscopy: a quick, inexpensive bedside exam using a short, lighted tube inserted into the anal canal. It requires no bowel preparation or sedation and gives the examiner a direct view of the internal hemorrhoidal tissue. Studies show anoscopy is more sensitive for detecting internal hemorrhoids than flexible sigmoidoscopy.
If you’re over 45 or have risk factors for colorectal disease, your doctor may recommend a colonoscopy to rule out other causes of rectal bleeding, such as polyps or inflammatory conditions.
How They Differ From Anal Fissures
Internal hemorrhoids and anal fissures share several symptoms, including rectal bleeding and itching, and both can result from straining. The key difference is pain. About 90% of fissures cause sharp pain, usually a tearing sensation during or right after a bowel movement that comes in episodes. Hemorrhoid discomfort, when present at all, tends to be more constant and dull. If your main symptom is painless bright red bleeding, hemorrhoids are more likely. If the dominant symptom is sharp, episodic pain with bowel movements, a fissure is the more common explanation.
Lifestyle Changes That Help
Fiber is the cornerstone of hemorrhoid management. Federal dietary guidelines recommend 14 grams of fiber per 1,000 calories, which works out to about 28 grams per day on a standard 2,000-calorie diet. Most Americans fall well short of that. Increasing fiber through whole grains, fruits, vegetables, and legumes softens stool and reduces the straining that worsens hemorrhoids. Drinking enough water is essential for fiber to work properly.
Beyond diet, a few practical habits make a real difference: avoid sitting on the toilet longer than necessary (put the phone down), don’t delay bowel movements when you feel the urge, and avoid heavy straining. Warm sitz baths, where you sit in a few inches of warm water for 10 to 15 minutes, can relieve irritation from prolapsed or symptomatic hemorrhoids. Over-the-counter creams and suppositories can temporarily ease itching and swelling.
Office-Based Procedures
When lifestyle changes aren’t enough, the most common next step is rubber band ligation. During this quick office procedure, a small rubber band is placed around the base of the internal hemorrhoid, cutting off its blood supply. The banded tissue shrinks and falls off within a few days. Success rates range from 69% to 97%, and it has better long-term results than other non-surgical options like injection therapy or infrared coagulation.
Rubber band ligation isn’t painless. At least 25% to 50% of patients experience mild anal discomfort in the first 48 hours. Dizziness or lightheadedness at the time of the procedure occurs in about 30% of people. Some delayed bleeding can happen 10 to 14 days later when the banded tissue separates. Serious complications are uncommon: a review of over 8,000 patients found severe pain in about 6%, significant bleeding in under 2%, and infection in less than 0.1%. Between 7% and 18% of people need repeat sessions for recurring symptoms.
When Surgery Is Needed
For grade III and IV hemorrhoids that don’t respond to office procedures, surgical options include traditional excisional hemorrhoidectomy (removing the hemorrhoidal tissue) and stapled hemorrhoidopexy (repositioning and securing the tissue back in place). Stapled hemorrhoidopexy generally involves shorter operative time, less post-surgical pain, and a faster return to normal activities. However, it carries a higher rate of symptom recurrence compared to traditional excision. Patients undergoing either procedure are typically discharged the following day.
Recovery from a traditional hemorrhoidectomy is notoriously uncomfortable, with significant pain lasting one to two weeks. Stapled procedures tend to have a shorter, less painful recovery. Your surgeon’s recommendation will depend on the size and grade of your hemorrhoids, whether you’ve had prior procedures, and your overall health.