I am without feeling in either of my little fingers and part of my thumb. This situation arose after a weeklong climbing trip that involved cramming my fingers into cracks of various sizes. Is the numbness permanent?

—Harriet

My best mate, Akadaka, and I were growing our mettle in Ratikon, a Swiss multi-pitching area with a ground-up bolting ethic that resulted in an alarming absence of said bolts. High on the sixth pitch of the death slab we’d chosen, fingers failing, I found myself mashing my tips behind a blade that bore remarkable similarities to my favorite cook’s knife. As I pasted my feet on the velvety limestone bonnet beneath me, my right hand blasted off the wall. Twenty feet out from the last bolt and reeling backward, I roared a roar that caused the vicar three villages north to raise a concerned eyebrow.

I averted a fall, but the tip of the ring finger on my left hand, having been subjected to the force of sheer necessity, went numb. It took a month before sensation returned.

Nerves do not like pressure—entrapment, trauma or otherwise. Pain, pins and needles, numbness, muscle twitching and weakness are all common symptoms of nerves suffering from assault. Take a spinal disc bulge in your neck, or low back, that touches the nerve root. Although these typically entail low-grade constant pressure, with enough force nerves can also be crushed, stretched and even severed without breaking the skin.

Injuring your digital nerve is a case in point. The nerve travels up the anterolateral aspect of each finger and, with enough sharp pressure, can be severely damaged. Because these nerves are sensory only, numbness is the usual outcome.

Nerves are slow to heal, and the loss of sensation can take months to return, or may never at all. There is little you can do other than wait and see. Most likely, sensation will return within a month or so.