Internal hemorrhoids are swollen blood vessels that form inside the lower rectum, above a boundary called the dentate line. Because this area lacks pain-sensing nerves, most people with internal hemorrhoids don’t feel them at all. The most common first sign is bright red blood on toilet paper or in the bowl after a bowel movement. Millions of adults have them, and most cases respond well to simple changes in diet and bathroom habits.
Where They Form and Why They Don’t Hurt
Everyone has cushions of blood vessels lining the anal canal. These cushions help with continence and are a normal part of your anatomy. When the vessels in the upper portion of the anal canal become swollen or engorged, they become what we call internal hemorrhoids.
The key anatomical detail is the dentate line, a ring of tissue about halfway up the anal canal that separates two different types of lining. Above this line, the tissue is similar to the lining of your rectum. It produces mucus and, critically, has no nerve fibers that detect sharp or burning pain. That’s why internal hemorrhoids typically cause painless bleeding. You can have significantly enlarged ones without any discomfort at all. Below the dentate line, however, the tissue is rich with pain nerves, which is why external hemorrhoids can be intensely painful by comparison.
The Four Grades of Severity
Doctors classify internal hemorrhoids on a scale from Grade I to Grade IV based on how far the swollen tissue drops (prolapses) out of the anal canal.
- Grade I: The hemorrhoid bulges into the anal canal during a bowel movement but doesn’t push outside the body. You won’t see or feel anything, though you may notice bleeding.
- Grade II: The tissue protrudes out during straining but slides back in on its own once you stop.
- Grade III: The hemorrhoid pushes out and stays out until you manually push it back in. At this stage, you may start to notice discomfort, mucus discharge, or difficulty keeping the area clean.
- Grade IV: The tissue is permanently outside the body and cannot be pushed back in. This is the most advanced stage and the most likely to cause persistent pain and irritation.
Most people who search for information about internal hemorrhoids are dealing with Grade I or II, where painless bleeding is the primary symptom.
Common Symptoms
The hallmark symptom is painless rectal bleeding. You’ll typically notice small amounts of bright red blood on the toilet tissue, dripping into the bowl, or coating the stool. The blood is bright red because it comes from engorged vessels close to the surface, not from deeper in the digestive tract.
Beyond bleeding, internal hemorrhoids can cause a feeling of fullness or pressure in the rectum, especially during bowel movements. If a hemorrhoid prolapses, you may feel a soft lump at the anal opening and notice mucus on your underwear. Itching around the anus is common when mucus from the prolapsed tissue irritates the surrounding skin. Pain is unusual with early-stage internal hemorrhoids, but it can develop once prolapse becomes significant or if the blood supply to a prolapsed hemorrhoid gets cut off (a condition called strangulation).
How They Differ From External Hemorrhoids
The distinction comes down to location, nerve supply, and how they feel. Internal hemorrhoids sit above the dentate line, are covered in mucus-producing tissue, and are painless in their early stages. External hemorrhoids develop below the dentate line, under skin that is packed with pain receptors. When an external hemorrhoid develops a blood clot (thrombosis), it creates a hard, extremely tender lump you can see and feel near the anus.
Internal hemorrhoids tend to bleed more and prolapse, while external hemorrhoids tend to cause more pain and swelling. It’s possible to have both types at the same time.
What Causes Them
Anything that increases pressure on the veins in the lower rectum can cause the anal cushions to swell. The most common culprits are straining during bowel movements (often due to constipation), sitting on the toilet for long periods, and chronic diarrhea. Pregnancy increases the risk because of both hormonal changes and the physical pressure of a growing uterus on pelvic veins. Obesity, heavy lifting, and aging also contribute, as the connective tissue supporting these blood vessels weakens over time.
A low-fiber diet ties many of these factors together. Without enough fiber, stools are harder and smaller, requiring more straining to pass, which places repeated pressure on the anal cushions.
How They’re Diagnosed
Internal hemorrhoids can’t be seen or felt during a standard external exam. A doctor will typically start with a digital rectal exam, then use a small, lighted tube called an anoscope to look directly inside the anal canal. Through the anoscope, internal hemorrhoids appear as purplish bulges in the lining.
One important caveat: finding hemorrhoids doesn’t automatically explain all your symptoms. Rectal bleeding attributed to hemorrhoids alone turns out to have an additional source higher in the digestive tract up to 50% of the time. If you’re over 45, have a family history of colon cancer, or your bleeding pattern changes, your doctor will likely recommend a colonoscopy to rule out other causes.
Lifestyle Changes That Help
For Grade I and most Grade II hemorrhoids, dietary and behavioral changes are the first and often only treatment needed. The single most effective step is increasing your fiber intake. Federal dietary guidelines recommend 14 grams of fiber per 1,000 calories you eat, which works out to about 28 grams per day on a standard 2,000-calorie diet. Good sources include beans, lentils, whole grains, berries, broccoli, and pears. If you can’t get enough from food alone, a fiber supplement works too. Increase your intake gradually over a week or two to avoid bloating.
Staying well hydrated makes fiber work better by keeping stools soft. Beyond diet, avoid sitting on the toilet longer than necessary (put the phone down), don’t strain or hold your breath during bowel movements, and go when you feel the urge rather than delaying. Warm sitz baths, where you sit in a few inches of warm water for 10 to 15 minutes, can relieve any irritation or pressure you feel after a bowel movement.
Office-Based Procedures
When lifestyle changes aren’t enough, especially for Grade II and III hemorrhoids, doctors can perform minimally invasive procedures in an office setting without general anesthesia. The most common is rubber band ligation. A tiny rubber band is placed around the base of the hemorrhoid, cutting off its blood supply. The tissue shrinks and falls off within a few days. About 89% of patients get full symptom relief from this procedure. Roughly 22% experience some anal pain afterward, and 18% have minor bleeding during healing, but serious complications are rare.
Other office options include injecting a chemical solution into the hemorrhoid to shrink it (sclerotherapy) or using infrared light to coagulate the tissue. These tend to be used for smaller hemorrhoids or when banding isn’t suitable.
When Surgery Becomes Necessary
Surgery is reserved for cases that don’t respond to office procedures, typically Grade III hemorrhoids that keep recurring and Grade IV hemorrhoids. It’s also sometimes needed for people on blood-thinning medications who experience repeated hemorrhoidal bleeding.
The traditional approach is surgical removal of the hemorrhoidal tissue. A newer option lifts the hemorrhoid back into its normal position and cuts off part of its blood supply using a stapling device. Long-term studies show both approaches produce similar results in patient satisfaction, symptom resolution, and quality of life. A third technique ties off the arteries feeding the hemorrhoid using ultrasound guidance. This approach causes less postoperative pain and shorter hospital stays, though at 12 months the outcomes are comparable to traditional surgery.
Recovery from hemorrhoid surgery varies by technique but generally involves one to two weeks of discomfort and limited activity. Most people return to normal routines within two to three weeks. Maintaining a high-fiber diet after any procedure significantly reduces the chance of hemorrhoids returning.