Hemorrhoids are a common condition involving swollen, inflamed veins in the lower rectum and anus, similar to varicose veins. They occur when increased pressure causes these normal vascular cushions to swell and stretch. Understanding the specific experience of internal hemorrhoids requires clarifying their location and how that affects the nerves in the area. This distinction is important because the symptoms can be subtle or easily confused with other conditions.
Defining Internal Hemorrhoids and Their Location
Internal hemorrhoids are clusters of swollen veins that form inside the rectum, originating above the dentate line. This line marks an anatomical transition point within the anal canal. The tissue above the dentate line is lined with rectal mucosa and has a visceral nerve supply.
External hemorrhoids develop below this line, under the skin around the anal opening, where the tissue has a somatic nerve supply. This difference in innervation dictates the primary sensation, or lack thereof, experienced by the patient. Internal hemorrhoids are typically not visible or palpable from the outside unless they protrude.
The Primary Symptom: Absence of Pain
The primary characteristic of internal hemorrhoids is the absence of pain. This is because the rectal lining contains only visceral sensory nerves. These nerves detect pressure, stretching, and fullness, but they do not register sharp pain like somatic nerves do.
Consequently, a person may not feel the presence of the swollen tissue at all. During a bowel movement, the movement of stool against the tissue may cause irritation, but typically not pain. An uncomplicated internal hemorrhoid remains largely “silent” in terms of discomfort.
If the hemorrhoid swells significantly or is subjected to extreme straining, the visceral nerves may register pressure or vague discomfort. True, sharp pain usually only develops if the hemorrhoid prolapses and the tissue is trapped, or if a complication like thrombosis occurs.
Visible Signs and Secondary Discomforts
While often painless, the most common symptom is bleeding. This blood is typically bright red, appearing on the toilet paper, dripping into the toilet bowl, or streaking the stool. Bleeding occurs when the delicate surface of the swollen vessel is damaged by friction from passing stool.
Another common sign is a feeling of incomplete evacuation (tenesmus) or a sense of fullness in the rectal area. As the hemorrhoid swells, it occupies space, leading to the perception that the bowel movement is not finished. The inflamed tissue can also produce a mucus discharge.
If the internal hemorrhoid progresses, it may prolapse, protruding outside the anal opening during straining. A prolapsed hemorrhoid may be felt as a soft, fleshy lump outside the anus. Once prolapsed, the tissue may cause secondary discomforts, such as mild irritation or itching (pruritus ani).
When to Seek Medical Evaluation
While most hemorrhoid symptoms are manageable at home, certain signs necessitate a medical evaluation to confirm the diagnosis and rule out more serious conditions. Any instance of rectal bleeding should be discussed with a healthcare professional, as bleeding can be a symptom of other gastrointestinal issues, including colorectal cancer.
Seek medical attention immediately if you experience significant or heavy bleeding, especially if accompanied by dizziness or faintness. A sudden onset of severe, constant pain signals a potential complication, such as a thrombosed or strangulated hemorrhoid, which requires urgent care.
If the color of your stool changes to a dark, tarry black, this may indicate bleeding higher up in the digestive tract and should be investigated. Persistent symptoms that do not improve after a week of conservative home care also warrant a doctor’s visit.