It's one of those words that's gotten more popular in health marketing in the last few decades, and people are willing to pay real money to do something about it.

But inflammation is a normal biological process that our bodies use to keep us safe.

We don't want to get rid of all inflammation.

So today we're going to dig into the inflammatory response and come away understanding why those health claims need a little bit more nuance attached to them.

Inflammation itself is an immune response to some kind of problem in the body.

That response might be acute, which means it comes and goes quickly, or chronic, it stays around longer.

It could be triggered by any kind of infectious or non-infectious problem in the body, anything from bacteria and a dirty cut, to frostbite, to a splinter.

Regardless of what initiates it though, the response is similar.

From just living and being a human, you're probably familiar with the five signs of inflammation firsthand: heat, redness, swelling, pain and loss of function.

And they range from mildly annoying to seriously debilitating, but they actually serve a specific role in protecting you from further harm and kicking off the healing process

Contrary to what some may think, the increased heat is not there to try to bake the infectious agent.

It's there because the blood vessels around the inflamed body part expanded, bringing more blood to that area.

That's also why the area gets more red.

You are passing more red blood cells through the inflamed tissue, just like how your cheeks get warm and red when you blush.

Our blood is warm, and with more blood flow, we feel more heat.

Along with more blood, the vessels that transport that blood expand and become more permeable, which fills that area with fluid and shows up externally as swelling.

Pain comes from the stimulation of pain receptors from the initial injury, or from the inflammatory response itself.

Finally, the loss of function could come from either increased swelling, which reduces mobility, or from healthy tissue being replaced with less flexible scar tissue over time.

And that's only what we see from the outside.

Our immune systems orchestrate all these different chemical messengers called cytokines. "Cyto" for cell, "kine" for movement.

They're chemicals that get cells to move to the inflamed area.

You may have heard about cytokines in the context of a cytokine storm before, when these messenger molecules recruit more immune cells, which release more cytokines, which recruit more immune cells...

And you get this feedback loop that can cause sepsis or death.

And during the normal acute inflammatory response, they're recruiting mostly white blood cells to the area to attack any pathogens.

And all of this is a thing so that your body can stomp out whatever trying to hurt it, whether it's a bacterial infection or a sprained ankle.

But sometimes this process takes a little bit longer.

Our bodies continue to ship chemical messengers and white blood cells to the site, and if that creeps into the multiple weeklong territory, it's classified as chronic inflammation.

You don't always need an acute inflammatory response to develop chronic inflammation though, like rheumatoid arthritis is an autoimmune disease that causes inflammation of the joints.

There was never one big injury that kicked it off.

Either way, chronic inflammation is where this whole inflammatory response gets more problematic.

For instance, patients with atherosclerosis, a narrowing of the arteries around the heart that predisposes folks to heart attacks, will have elevated cytokines and inflammatory proteins in their blood.

Because of that, health care providers might look for inflammatory markers in your blood as a way of predicting your risk of heart disease.

If your liver experiences too much inflammation, you can permanently damage the hepatocytes, cells that play a big role in metabolism and immune function.

Your lungs are in the same camp.

One of the reasons that cigarette smoking is so lethal is because it causes a constant inflammatory response in the lungs.

That can narrow and stiffen the tiny airways in your lungs, making it harder for air to pass through.

So in the case of livers and lungs, chronic inflammation literally leads to worse organ function.

With that in mind, you can see why people would want to reduce inflammation, and certain drugs do that but through different mechanisms.

Like if you've gotten injured, you might have taken ibuprofen, a non-steroidal anti-inflammatory drug ,or NSAID, for the pain.

It works by inhibiting certain enzymes in your stomach that make compounds called prostaglandins.

Those prostaglandins keep the inflammation process going, so by inhibiting the enzyme that makes them, ibuprofen reduces inflammation.

Or people with rheumatoid arthritis might take a drug that reduces inflammation by inhibiting one of those chemical messengers called tumor necrosis factor alpha.

Both drugs results in a reduced inflammatory response, but take different paths to get there.

Knowing all that, we can't say that inflammation is clearly bad or clearly good.

We need this process in order to survive, but too much for too long can be harmful.

Thanks for joining us for season two of Seeker Human!

I had so much fun with season one, and I'm stoked to bring you more videos on this channel.

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