Quelling Inflammation Is Not the Same as Resolving It

When a splinter lodges in a finger, the spot stays red for a day or two even after it is removed. By the third day, you can no longer tell where it was. The splinter came out on the first day, but it takes a few more days for the spot to settle down.

The word “settling” covers two different paths. One is pressing down on what has been switched on. The other is the body sending a separate signal to bring things to a close. On the surface, both look the same — the redness fading — so at the time it is hard to tell them apart.

The Path of Pressing Down

When inflammation occurs, a number of substances are produced at the site. They open the blood vessels to cause swelling, raise temperature, and sensitize nerves. Anti-inflammatory drugs block the pathway that produces these substances. When less is produced, the swelling, heat, and pain go down together.

It is a certain, fast action. And where inflammation has switched on strongly, this path comes first. When too many immune cells crowd in, they can damage tissue more than the infection or injury itself did. In that case, pressing down quickly protects the tissue. This is what conventional anti-inflammatory drugs do well.

The Path of Bringing It to a Close

The body does not wait until the inflammation has fully passed to bring it to a close. That process begins not long after the inflammation itself starts. While inflammation is at its height, the kinds of substances produced at the site change partway through. Where substances that called in more cells were being made, substances that end the process begin to appear instead.

These are not blocking substances but instructing substances. They bind to their own receptors and switch on the work that needs to be done. They make the cells that gathered and finished their job die on schedule, and have macrophages engulf and clear them away. This same signal even directs the resurfacing and closing of the cleared site. These substances carry a name of their own: specialized pro-resolving mediators.

So pressing down and bringing to a close are different in nature. The former reduces what is happening; the latter switches on what needs to happen. A drop in intensity does not mean the cleanup is finished along with it.

If the ending signal does not switch on in time, the calling substances keep being produced. The cells keep crowding in without stopping. Then, instead of ending, the inflammation drags on.

What Is Not Cleared Away Calls Again

If the cleanup does not finish, dead cells and debris are left behind at the site. What remains becomes a signal all over again. The body reads fragments leaking out of damaged or dead cells as an alarm warning of danger, and those fragments switch the immune system on again and again. It is not as strong as the first time, though. It runs on at low intensity for a long time.

That is why it looks different from the start. It does not turn red and swollen, and the temperature does not rise much either. But fatigue does not lift even with rest, the site that hurt becomes sensitive to the smallest stimulus, and whatever you do, it takes a long time to bounce back.

Nor does it stay confined to one place. The same thing happens even in places with no visible wound, because what sounds the alarm is not the wound but the substances left uncleared. And if this state continues, even the order in which tissue heals gets thrown off.

This is why, even after pressing down hard, things come back up again after a while. Pressing down reduces the amount currently being produced, but if the source of the alarm remains, the switch turns on again. I discussed this distinction earlier in Two Ways to Calm Inflammation.

If It Is Strongly Switched On Right Now, Check First

For a body that is strongly switched on right now, the order is different. If fever continues, or a joint is swollen and painful, or inflammatory markers are clearly high, testing to find the cause comes first. When those signs are present, I recommend seeing internal medicine first. A state that needs to be pressed down is different from a state that has failed to reach a close. Mistaking one for the other costs time.

What I Look At First in a Body That Drags On

When I look at a body that has been dragging on, I look first at why the alarm keeps sounding, rather than at how much the intensity has come down. I check whether the gut has become permeable and is leaking its contents, whether the body has been unable to get time to recover, and whether there is a place that has been under pressure and worn out for a long time.

Saying an illness has gone on for a long time means the illness has settled into the body. In a body where it has settled in this way, things happen that lowering the intensity alone cannot explain.

What has been pressed down and what has ended look the same on that day. They diverge months later. One passes without a trace; the other stays on, without ever turning red again.

In a condition that drags on, what I ask is not what is still switched on, but what has not yet come to a close.

Written by Dr. Heo Ji-young (PhD in Korean Medicine Pathology, Kyung Hee University · former Research Professor of Herbology, Kyung Hee University)