It Hurts More When the Numbness Lets Go

Straighten a leg you had crossed for a long time and it prickles. Sleep on your arm and for a while afterward it feels like someone else's. Standing up after crouching to work is the same.

Most people feel it this way: it hurts more when it lets go than while it was pressed.

It is common enough to pass over, but I think of this sensation often in the clinic. Long-standing pain has the same grain to it.

Something separate happens on the way back

A place that has been getting less blood has been running lean. Making energy with little oxygen tilts the acidity of that place, and the nerve endings there grow sensitive to that tilt.

Then blood flows again and oxygen arrives all at once. Recovery is not the only thing that happens. Things to clear away appear as well. What happens when blood stops and then flows again carries a name — ischaemia–reperfusion injury. In cardiac care this part has been well known for a long time. Reopening a blocked vessel is standard treatment and it saves people, yet the stretch right after it opens is treated as a phase to be managed on its own.

The direction of the conclusion matters here. This is not a reason to delay bringing things back. It means bringing them back while also watching what happens on the way back.

What three still hours did

What we meet in the clinic is not an event of that size. It is something much milder, repeated over a long time.

There is a study that had people sit for 3 hours and measured the response of the leg vessels. In the leg left still, the vessels' ability to widen fell from 4.5% to 1.6%. Yet in the same person's other leg, which was allowed to fidget, it improved instead. The trouble was less the 3 hours of sitting than the flow standing still for those 3 hours. (The inner surface of a vessel feels the flow)

The count adds up

A place held under pressure in one posture, a place stiffened so blood passes through less, a place swollen so the pressure has risen. Such places go hungry a little and come back a little, several times a day. Each round is small, but the count adds up.

I think this has a hand in why a place with long-standing pain is so sensitive. That place has already gone hungry and come back many times. (Supply alone does not heal)

I do not release it hard all at once

I do not release a long-stiffened area hard in one go.

Release it hard and the moment feels good. But the wider the stiffened area, the more a border forms between what has been released and what has not. Cases where people tell me it felt heavier and more swollen the next day come from places like that. So I divide the area and work through it over several visits.

I do not look at one side only when using herbal medicine either. Some herbs are read as sending blood into a narrowed place (cinnamon twig, dried ginger); some help what has come in drain away rather than pool (Astragalus root, Atractylodes rhizome). Push only, and it pools. The way out has to be opened along with it.

The force going in, the force going out, and the hour each of them arrives are all different. It is less that one herb takes one job, and more that several hands push from different places in the same direction.

When to go to the hospital first

If one leg or arm suddenly swells and hurts, if the color changes, or if numbness does not let go and the sensation disappears — that is a different matter. Time counts there, so please have it checked first.

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Hurting on the way back is not only a sign that something is going wrong. It is true, though, that the moment is a phase to be handled on its own.

So I do not hurry when releasing what has stiffened. Not to delay bringing it back, but to bring it back evenly.

Sources

• After 3 hours of sitting the vessel response fell in the leg left still, while the same person's other leg, allowed to fidget, improved instead — American Journal of Physiology–Heart and Circulatory Physiology, 2016
• Reopening a blocked vessel is standard treatment, yet injury is added at the moment blood returns, through reactive oxygen species and calcium overload — Experimental and Therapeutic Medicine, 2022

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