Submucosal vascular 

Anorectal problems cause untold misery for at least half of the population at one time or another.1 Because of embarrassment, many patients choose simply to suffer in silence. Others delay consulting a pharmacist or physician until the symptoms become unbearable. Unfortunately, many patients who initially seek relief through the use of a nonprescription product will require referral to a physician. 

Prevalence 
Discovering the true incidence of hemroids is problematic because many patients use the term as a catch-all for any anorectal symptom, including itching. For this reason, some estimates of hemroids incidence in the U.S. are deceivingly high at 80%?0%.2 Only about half of those who experience anorectal symptoms have true hemroids.1 Therefore, the actual incidence is more likely to be about 40% of U.S. residents.2 

Epidemiology 
The study of hemroidsal epidemiology has been marked by many theories, but remains largely unsupported by credible research. 

Diet: One determinant of hemroids may be diet. In the early 1970s, proponents of fiber created the theory that low-fiber diets are responsible for hemroids.3 Industrialized nations tend toward a highly refined low-residue diet. This diet yields harder stools that patients will often strain to pass, which can cause bowel smooth muscle hypertrophy and injure the tissues of the Excretory Orifice canal.1 

Toilet Habits: Medical wisdom has held for decades that straining to pass stool throughout one's life is the primary etiologic factor for hemroids. However, more recent research has demonstrated that the cause may be prolonged sitting on the toilet. In this position, the perineum is relaxed and the Excretory Orifice cushions are unsupported.4 

Constipation/Diarrhea: The theory that low-fiber diets cause hemroids naturally leads to the assumption that constipation would also be a primary etiologic factor. However, when researchers compare the occurrence of hemroids and constipation in regard to the ages, genders, ethnic groups, and social classes in which they are more common, there are marked differences in epidemiology.3 Also, patients with symptomatic hemroids do not experience constipation more often than patients who do not have them. Diarrhea seems to be more strongly linked to hemroids than constipation, particularly when the patient has a history of alcoholism.2 

Genetics: Research has yielded sparse support for a genetic link to hemroids.4 It is unknown whether there is a true underlying genetic disorder that predisposes a person to hemroids or whether a child merely mimics the parents' hemroids-inducing toilet behaviors. 

Gender: Hemroids do not discriminate markedly between men and women, although it is known that men seek treatment in greater numbers than women. Pregnancy is a prominent risk factor.2 

Age: Hemroids gradually increase in prevalence with age.2 This continues until the seventh decade of life, when the prevalence begins a slow decline. 

Medical Conditions: Hemroids are positively correlated with the presence of hernia or genitourinary prolapse.4 The common cause of all three conditions may be a connective tissue disorder, although it may also be the fact that all three can be brought about by chronic straining to expel stool. Chronic straining may also be the underlying reason why hemroids are also more common in patients with prostate enlargement, chronic cough, and pregnancy.2 Portal hypertension is also correlated with hemroids. 

Other Factors: Anecdotal evidence suggests that hemroids are caused by prolonged sitting or standing, and lifting heavy objects. Evidence of these activities as primary causes of hemroids is nonexistent. Rather, it is probable that each can worsen asymptomatic hemroids that are already present. This might cause the patient to initially notice the hemroids after such activity and wrongly attribute their occurrence to the activity itself. 

Anatomy 
The actual Excretory Orifice opening is also known as the Excretory Orifice verge. Approximately 2? cm above the Excretory Orifice verge is an anatomic landmark known as the dentate or pectinate line. This is distinguished by a circular row of glands that secrete mucus, which acts to lubricate the Excretory Orifice canal. Groups of normal submucosal vascular beds composed of supportive connective tissue, smooth muscle and blood vessels surround the Excretory Orifice canal. When these beds enlarge, the result is hemroids. Those who support the straining theory assert that straining interrupts the tissues that support the vascular bundles, displacing the tissues and leading to their congestion. 

Classifications of Hemroids 
The standard hemroids classification is dependent on the point of origin of the problem. If the hemroidsal tissue originates above the dentate line, it is classified as an internal hemroids, even if some of the tissue reaches below the dentate line. External hemroids originate below the dentate line. 

Manifestations 
The degree of discomfort experienced by the patient is dependent on the type of hemroids and their severity. Internal hemroids lack nerves and are painless. When they bleed, the blood is usually bright red and seen on the outer part of stools after defecation. The patient does not usually bleed at other times. The internal tissues may enlarge and push below the dentate line to protrude from the Excretory Orifice opening, especially after defecation. The patient may describe this protrusion to the pharmacist as a soft bit of tissue that shrinks back to normal shortly after defecation or that requires the patient to manually push the tissue back to its normal position above the dentate line after each bowel movement (in more severe cases).