Starting a few years ago, I ran into an oddity while out hiking, where I get a tingling/numbing sensation in my fingers (to start) but soon escalates to include the whole arm, face, sometimes chest. Not a lot different from the sensation of certain drugs (N2O comes to mind).
It doesn't happen all the time (maybe three times a year), mind you, and doesn't seem to be dangerous (no loss of coordination, consciousness, or anything like that) and it goes away within about 5 minutes if I stop. There are certain conditions that also seem to apply:
* Only happens when going downhill. If I start up a hill again it goes away within minutes
* Only happens at lower altitudes, usually less than 6,000ft
* It also only seems to happen after I've been out hiking for 3-4 days.
It doesn't seem related to the long-distance nature of some of my hikes, as it can happen on shorter outings of 7hrs or less.

I described it to a few other partners in crime, but none of them reported anything similar. It puzzled me for the last few years and I only recently determined the cause. I'm curious if anyone else has run across this or what one of our medical practitioners might make of it. I'll reveal the cause later - it may surprise you. Or may not.

Oooo I like this game. I'm going to guess that you were breathing too deeply or too rapidly, leading to respiratory alkalosis and parasthesia.

"Not a lot different from the sensation of certain drugs (N2O comes to mind)."

Umm, do you get giggly and light headed too?

catullus wrote:Oooo I like this game. I'm going to guess that you were breathing too deeply or too rapidly, leading to respiratory alkalosis and parasthesia.

Dang. 9 minutes from post to answer. You're good.

I spent (far too) much time thinking it was related to exhaustion, dehydration, low food, heat, or other causes. Then when it happened this last time, I noticed I was breathing deeply to the count of my footsteps, a habit I've gotten into to help with the uphill at higher altitudes. Apparently not so great for downhill. I continued hiking at the same rate but breathing through my nose, and the symptoms went away after five minutes. Then I induced them again, just to be sure. And 'cause it was fun. Hah!

Bob Burd wrote:

catullus wrote:Oooo I like this game. I'm going to guess that you were breathing too deeply or too rapidly, leading to respiratory alkalosis and parasthesia.

Dang. 9 minutes from post to answer. You're good.

I spent (far too) much time thinking it was related to exhaustion, dehydration, low food, heat, or other causes. Then when it happened this last time, I noticed I was breathing deeply to the count of my footsteps, a habit I've gotten into to help with the uphill at higher altitudes. Apparently not so great for downhill. I continued hiking at the same rate but breathing through my nose, and the symptoms went away after five minutes. Then I induced them again, just to be sure. And 'cause it was fun. Hah!

If only SP were for a grade (I'm in med school)....

Well, as someone with a significant brain injury, I'd say: boo-hoo!

Ha ha! No, really; I've had friends with similar problems. They were told to flex their hands while moving; one guy even carried a rock in each hand and periodically squeezed each rock to ensure circulation. (I'm serious.)

But go with the rectal probe just to be safe; maybe a coffee latte enema.

catullus wrote:If only SP were for a grade (I'm in med school)....

Those Stanford guys are smart. Geniuses. Good climbers, too. How many university presidents have a cool peak named after them?

whoa... mount jordan is named after david starr jordan? cool bit of history

catullus wrote:whoa... mount jordan is named after david starr jordan? cool bit of history

Hmmm. Good medical students. Lousy historians.

"Named in 1925 by the Sierra Club in honor of the educator and scientist David Starr Jordan (1851-1931), president and chancellor of Stanford University. Jordan himself had proposed the name Crag Reflection [Lake Reflection is on the peak's north side] for a part of the peak."
- Erwin Gudde, California Place Names

Nearby Mt. Stanford had been named in 1896 by Bolton C Brown.

"Not many college presidents have stood on the summit of a high mountain named for their institution. On August 16, 1899, President David Starr Jordan, of Stanford University, did exactly that. 'I have never seen a more magnificent mountain panorama!' he exclaimed. Dr. Jordan was well qualified to speak of mountain panoramas; some years before he had climbed the Matterhorn in Switzerland. The Stanford party, which included Mrs. Jordan and several of the University's professors, spent many pleasant days at the head of Bubb's Creek, where Dr. Jordan gave names to a number of features, including 'Ouzel Basin,' suggested by Muir's description in The Mountains of California."
- Francis Farquhar, History of the Sierra Nevada

more stanford climbing history:

http://www-sul.stanford.edu/depts/ssrg/misc/sac.htm

p.s. to clarify, was stanford undergrad, now med student at CU, just hadn't updated my location till now =)

Seriously, there used to be a condition called "rucksack palsy," and one symptom was numbness in the hands. The straps on the pack interfere with the nerves and blood vessels in the shoulders. http://www.drdchiropractic.com/files/BA ... SAFETY.pdf

Usual diagnostic is a rectal probe.

knoback wrote:I don't know man, are you sure it's not a tumor? You may need a total body MRI, a spinal tap and a rectal probe just to be sure. Hell, you ought to just have those things done anyway. Everybody should. Everybody.