We all have hemorrhoidal veins in the anus, anal canal, and
rectum. These veins do not have valves, which would normally
help support and distribute the weight of the blood. Many
factors can cause undue pressures on these veins, which can
then cause these veins to become distended and swollen hemorrhoids.
Straining during bowel movement
One of the most frequent causes of hemorrhoids is straining
during bowel movements. Forcing for too long or too hard,
because of diarrhea, constipation, or bad bathroom habits
(such as reading on the toilet) is actually attributed to
the majority of hemorrhoids cases.
It is interesting that some have argued that the design
of the sitting toilet actually contributes to straining
- hemorrhoids are virtually unknown in countries with squat
toilets.
Genetics
Inherited characteristics such as weak vein walls can result
in tendencies to develop hemorrhoids. Heredity alone, however,
does not usually lead to a hemorrhoid without additional
factor(s), such as a bad bathroom habit or a job that requires
standing or sitting for prolonged periods.
Note that although "bad genes" are often blamed,
for some, hemorrhoids actually are caused by learned behaviors
- these people are simply following the lifestyle and bad
bathroom habits of their parents.
Western Diet
Although it is very common in Western countries, hemorrhoid
is actually rare in cultures that eat a fiber-rich diet.
A typical Western diet is rich in refined flour, sugar,
animal protein, and fiber-depleted carbohydrates, whereas
Asian and African diets are rich in natural grains, plant
fibers and roughage.
This leads people to think that diet plays a big role: foods
that are lacking in fibers actually create stool that is
harder to pass. This results in straining during a bowel
movement, and thus hemorrhoids.
Indeed, there is some evidence that there is a direct relationship
between the amount of fiber in the food, the time it requires
to ingest and eliminate the food, as well as the weight
and consistency of stool. For example, a typical African
villager easily passes about 400 to 500 grams of moist stool
approximately 35 hours after eating. A typical Westerner,
however, passes 150 grams of stool approximately three to
five days after eating!
Interestingly, the incidence of hemorrhoids often increase
as the society becomes more affluent and its diet becomes
more Westernized.
You may ask: if it's so bad, why does Western food processing
get rid of fiber in the first place? Fiber is refined out
of flour and other foods for two main reason: consumer convenience
and profit for the food manufacturers. It turns out that
without the fibers, food is easier to chew and can be swallowed
more easily. Also, it takes less digestive gastric juices
to process, thus making more room in the stomach for food.
This means that consumers can actually eat more of processed
food, therefore increasing the profit of food manufacturers.
Indeed, prior to the introduction of the steel roller mills,
which deplete fibers from flour, in the 1880s, hemorrhoids
were quite rare even in Western countries.
Pregnancy
Another of the most common causes of hemorrhoids in women
is pregnancy: the extra weight of the uterus adds great
pressure on the rectal veins. For women who already have
hemorrhoids, pregnancy can definitely make their hemorrhoid
condition worse.
Even women who do not develop hemorrhoids during pregnancy
can still get them because of long and arduous labor and
delivery, or because of constipation that arise after childbirth.
For example, in the days and weeks after vaginal delivery,
some women regularly postpone bowel movements because of
tenderness in the anus and perianal area.
See Hemorrhoids and Pregnancy
Postponing bowel movement
Sometimes when "nature calls", there is no toilet
nearby. Usually, by postponing bowel movement, the urge
to defecate goes away and does not return until after eating
another meal. While occassionally postponing bowel movement
does no harm, doing it regularly can contribute to hemorrhoids.
Here's why: the longer fecal matter remains in the colon,
the drier it becomes and therefore the harder it is to pass
without straining. Repeated inhbition of the urge to defecate
can also result in weaker signals to the rectal muscles
to pass stool. Eventually, it may be difficult to pass stool
naturally without some straining.
Also, a colon filled with fecal matters is heavy and exerts
pressure on the blood vessels and veins of the anus and
rectum. This can cause these veins to swell and become hemorrhoids.
Diseases
There are several diseases that can actually lead to the
development of hemorrhoids. Of these, the most serious is
rectal cancer, which causes a false "call of nature",
thus encouraging the patient to go to the bathroom and strain
unnecessarily.
Enlargement of the liver, often found in people who abuse
alcohol, can create extra pressure on the hemorrhoidal veins.
Other digestive diseases, such as intestinal tumor and irritable
bowel syndrome, can interefere with normal elimination or
cause constipation.
Lastly, although heart attack does not cause hemorrhoids,
it does increase venous pressure and therefore can make
an existing hemorrhoid worse.
Bouts of diarrhea
Diarrhea is the body's way of getting rid of bacteria from
its digestive system. It is commonly caused by contaminated
food. However, diarrhea can also be caused by an allergic
reaction to food and milk, by stress and anxiety, as well
as by an adverse reaction to medication and laxatives.
In the case of diarrhea, the expulsive force of the watery
stool can damage rectal veins and lead to hemorrhoids.
Constipation
Paradoxically, the opposite of diarrhea can also lead to
hemorrhoids! Constipation is defined as infrequent bowel
movements or the difficulty in passing stool. The longer
the stool remains in the colon, the drier it gets. After
a certain point, usually a fair amount of straining is required
to pass the dry and hard stool.
A common condition in the elderly,
constipation is one of the major causes of hemorrhoids in
this segment of the population.
Extreme physical exertion
Laborers and weightlifters often hold their breath or grunt
while lifting heavy objects. This forces air downward in
the lungs and exerts pressure on the diaphragm, which in
turn exerts pressure on the abdominal organs and rectal
veins.
Note that weightlifters can also get hemorrhoids because
they eat a lot of animal proteins in order to gain bulk
and mass.
Prolonged sitting or standing and lack of exercise
Sedentary lifestyle, lack of exercise, as well as jobs
which require prolonged periods of sitting and standing
can lead to, or exacerbate, existing hemorrhoids.
