Kidneys: The Unsung Heroes Running Your Body’s Factory

Kidneys are a big deal. I said this yesterday, but it bears repeating since it’s World Kidney Day. How and why are they so important? I’m glad you asked. Kidneys do more than most think. Rather than spew facts, I’ll run a (hopefully) funny director’s commentary. Here are a few of these vital, emphasis on vital, things these small bean-shaped babies are responsible for.

First, they filter blood and remove waste. Remember when I said without them, someone’s blood would be muck – here we go. And, of course, there was my obsession with pee. Here’s why. Kidneys filter roughly 50 gallons of blood daily. No, that is not a typo. It removes toxins, excess salts (sodium is one way a person retains water), and “waste products.” That waste and extra fluid is turned into, you know it’s coming, pee. Many medications are also filtered out, which is why what you take cannot be on the naughty list (aspirin, basically, any anti-inflammatories) if you have kidney issues. Creatinine is the biggie for us kidney patients. We know this word well. It’s one more thing filtered out to be emptied by a trusty bladder.

Aside from flushing out the bad, kidneys are meant to keep the good via reabsorption, keeping things like proteins and blood cells in the bloodstream along with nutrients such as glucose, amino acids, and electrolytes. They also reabsorb water to keep people from getting dehydrated, but fluid retention is a sore subject with kidney patients and one of the main reasons people receive dialysis. We can’t get rid of our water! That brings us to the next item, but before that, what’s astounding is filtering all the blood in the body only takes thirty minutes. Dialysis takes three times that and is still not as effective. Dialysis isn’t just evil; it’s not efficient. However, I’ll not rag on dialysis in this post, but, for real, evil. Moving on…

Kidneys regulate fluid in the body, striking a balance. Honestly, they’re the body’s dams. If you’re dehydrated, the kidneys retain fluid; if you’re overhydrated, they let it go. How? Pee. Yes. Getting borderline gross for a moment if you don’t like reading all about urine – when someone is dehydrated, their pee is darker because the kidneys are holding out. When it’s lighter, someone is hydrated. This is why kidney docs don’t only care if you’re peeing, but what color it is, testing it for blood and protein in the urine (not in the plus column), and so on. However, let it be known that kidneys regulate fluids through urine. See, it’s all about the pee.

Your kidneys “release” when you have enough or too much, and they hold out, and what’s in the bowl is darker when you’re dehydrated. It’s about production, how it’s packaged, its label, all of it (output, color, if blood or protein is in your urine, etc.). See, factories. Factories that are selling urine.

Next up, kidneys balance electrolytes and minerals. I’ll just mention the biggies: sodium, potassium, calcium, phosphorus, and magnesium. (I didn’t know the last two were in the body until my kidneys decided to take a swan dive. Also, chocolate has phosphorus, which is one more reason I am not strong enough for a kidney diet. I’ll take Death by Chocolate for 20.)

These biggies are important, and all serve a purpose, with the kidneys pulling their strings, making them their puppets. Kidneys adjust sodium levels to regulate blood pressure and nerve function, maintain potassium balance to prevent certain heart conditions such as arrhythmias (irregular heartbeats), and control calcium and phosphorus levels, working with Vitamin D to keep bones strong. I missed magnesium, but it matters somewhere. Kidneys filter out excess electrolytes (those discussed among others) because too much of a good thing is not so good. For example, too much potassium can cause irregular heartbeats or strain on the heart. On the other hand, too little calcium means fragile bones. As someone with brittle bone disease, I have enough of that already, thanks.

Summing it all up, which I guess I could have done from the start, keeping these electrolytes in check is extremely important. Electrolyte balance is crucial for nerve function, nerve signals, muscle contractions, heart rhythm, and heart function. Imbalances can quickly lead to muscle weakness, heart problems, breakable bones, excess fluid retention, and much more.

Now, let’s talk about pressure. Blood pressure. Yeah, kidneys have a big say in this, too. I have two options: dumb it down or pull out a medical degree to explain how kidneys have their way with this. Dumbed down: Kidneys regulate blood pressure by controlling blood volume and releasing renin, an enzyme that influences blood vessel constriction. When blood pressure is too low, enter renin. If one’s blood pressure is too high, the kidneys retain more sodium and water to bring it down.

Some people may want a little more, and digging in is not something I’m fully qualified or very interested in, so I will try to keep this balanced. Kidneys control one’s blood pressure using the Renin-Angiotensin-Aldosterone System (RAAS). When someone’s blood pressure is too low, it releases renin, which I mentioned in my dumbed-down version. This release starts a chain reaction, which I will not break down for the sake of balance and my brain. The renin activates something that is converted into something else, which causes one’s blood vessels to constrict, raising blood pressure. This signals the adrenal glands to release aldosterone, which makes the kidneys retain sodium and water, further increasing blood pressure. If this didn’t seem simple, I left out special baroceptors and how the liver and lungs interact and convert all the names of things I also skipped. Balance. For people with kidney disease, things swing in favor of high blood pressure, which isn’t something you want to live with 24/7.

I only prefer for my blood pressure to be high if I’m in intense pain or furious, and from experience with my heart – I never (all caps) prefer low blood pressure. Luckily, without medications, my kidneys and heart cancel each other out, leaving me with a “normal” blood pressure (that sometimes borders low blood pressure but is still within bounds, so I’ll take it).

Good God, it’s time to talk about hormones. Kidneys produce several, including the most critical. Remember people, factories. I’m staring at the screen, thinking, “How TF do I dumb this down?” I’m going to skim. First, it produces renin. I’ve already gone into it and its importance. One down. The other two I’ll deal with are Erythropoietin (EPO) and Calcitriol (Active Vitamin D).

Erythropoietin (EPO) stimulates the bone marrow to produce red blood cells. EPO is what I wish I had most back in the day. My bone marrow was seriously suppressed, and like my kidneys, my bone marrow went on strike, or this aspect of it. Remember all those blood transfusions I mentioned in my last post? Here’s why. The kicker, the blood cells I did have were splitting apart; I couldn’t even keep what I had. Talk about anemic. Aside from the drugs and treatment, this was the biggest factor regarding my exhaustion. Anemia equals “fatigue” (exhaustion). Low oxygen levels trigger more EPO to combat anemia. A little late with that.

The other, Calcitriol (Active Vitamin D), is simpler: it’s all about bones. Calcitriol (Active Vitamin D) maintains bone health by helping the body absorb calcium from food. (It’s the same with phosphorus, and it’s for the same purpose, to put it out there.) Kidneys help convert inactive Vitamin D to Active Vitamin D (Calcitriol) to help those bones. Kidney disease means, like EPO, there is a halt on the Calcitriol assembly line causing bone problems such as osteoporosis. Wow, this one was much simpler.

Next (don’t worry, we’re at the end; just one more thing after this) is pH regulation. I am not a chemist, so this will be the briefest. Kidneys help maintain the body’s acid-base balance, preventing it from becoming too acidic or alkaline. (The ideal pH is 7.35-7.45, supposedly. I don’t know what that is; I just wanted to sound smart.) If blood is too acidic, the kidneys excrete and reabsorb things with asterisks and small numbers underneath them. If the blood is too alkaline, they do the same, but now they absorb what was excreted (I think that word sounds gross, but I have nothing else) and excrete what was absorbed when the blood was too acidic. Trying to sound smart again: There was all this stuff about ions, bicarbonates, and exchanges of such. If that meant what I wrote, I did it better. People with kidney problems can have dangerously acidic blood. I have no further comment.

Finally, drugs. The kidneys typically kick their butts (toxins’ butts, too) by filtering them out – thank you, pee. Kidney issues mean that kidneys get their @sses handed to them, full stop. What do I mean by drugs? I mean damn OTC (over-the-counter) medications. Antibiotics, painkillers, NSAIDs (ibuprofen, anyone?), chemotherapy drugs (laughing hysterically), and blood pressure medications, which is kind of ironic since kidney disease can cause chronic high blood pressure.

Toxins include alcohol, pesticides, heavy metals, and other harmful substances. Kidneys also filter out contrast dyes used in different medical testing (MRIs, CT scans, etc.), but I didn’t know if I should count this as a drug or toxin. If kidneys can’t get it together to bring it home, it can cause nausea, confusion, and even a coma. That last one surprised me.

*This is why I clear it with my kidney doctor whenever another doctor prescribes medication. Not the prescribing doctor who says it’s fine, a pharmacist echoing it, or if there is no warning regarding one’s kidneys. No. Until I receive clearance, I hold off. I refuse to die (again) for lack of due diligence.

Okay, I’m tapping out. I think it’s fair to say that the kidneys are one of the most important organs in the body. It’s the body’s factory, waste management system, dam, and product line, and going out on a limb, either make up or keep the peace regarding our blood’s composition. It affects the entire body, and when they go haywire, it messes with your blood, bones, hormones, heart, electrolytes, etc. Many things, including other essential organs, depend on properly functioning kidneys.

And that does it. Happy World Kidney Day, everyone! May your kidneys be with you.