Whats a Diuretic?

What's a Diuretic?

QUESTION: I have been taking a medication for many years, called a diuretic.
I know it is a water pill, but that's all. Recently you write that we should
ask questions about our medications, so I am asking you: what's a diuretic?

ANSWER: I think I suggested you ask your doctor about medications, but if you
are asking me, I am happy to be your doctor, at least for now. Simply put, a
diuretic is a medication the increases the production of urine. Our kidneys
are in charge of that function and manufacture urine in a two step process.
The first step is to "filter" the blood through the clump of capillaries and
tubules that form a structure called a "glomerulus".

This produces a liquid
that passes through the tubules of the kidney to reach the main tube that
passes to the bladder (ureter). As the liquid passes through the tubules, new
chemicals are excreted into the liquid, while some precious chemicals and
water itself is reabsorbed back into the body. The final fluid that passes
down the collecting ducts is called urine. The structure that includes a
glomerulus, the tubules and the duct is termed a "nephron" and is the basic
anatomical and physiological structure that kidneys are made of. Now if you
have that all clear, I can describe just how diuretics work. They may either
increase the rate at which the glomerulus works, producing more basic fluid,
or they may decrease the reabsorption that takes place in the tubules. Either
action results in the production of more urine. Different chemicals that are
used as diuretics act on different parts of the nephron system, and so
physicians choose carefully, prescribing the one that is best for their
patient's condition. Diuretics may be used to prevent or eliminate swelling
(edema), control hypertension, and treat heart failure. The next question to
ask your doctor is "What am I taking this medicine for?" Sorry, I can't
answer that one for you.