[up2date]

Hi,
Need some insight into AMS.
Some people experience motion sickness and tend to throw up all along the journey. But the moment they are out of the vehicle or sleep they feel OK.
This could happen even at 2000m above sea level.

Is this symptoms of AMS??

[up2date]

What I actually meant was, do pple prone to motion sickness tend to hit AMS easily?

[Sunilg]

I DONT think there is ANY relation between motion sickness and AMS. AMS strikes you because of low content of O2 in the air as well as low atmospheric pressure.

Yes, vomiting is a symptom of AMS, but its not JUST vomiting. Low oxygen can cause anoxic brain injury, which may in turn affect ANY part of the body, and can be fatal.

EDIT: Motion sickness: The most common theory for the cause of motion sickness is that it evolved as a defense mechanism against neurotoxins.[4] The area postrema in the brain is responsible for inducing vomiting when poisons are detected, and for resolving conflicts between vision and balance. When feeling motion but not seeing it (for example, in a ship with no windows), the inner ear transmits to the brain that it senses motion, but the eyes tell the brain that everything is still. The area postrema will always believe the inner ear signal over the eyes, as the eyes are more susceptible to trickery (see optical illusion). As a result, the brain will come to the conclusion that one is hallucinating and further conclude that the hallucination is due to poison ingestion. The brain responds by inducing vomiting, to clear the supposed toxin.
Source: Wiki 'the God' Pedia

to elaborate further; there is a fluid filled chamber inside our ear (vestibule system) which along with other sensory systems is responsible for maintaining the balance of our body. there are multiple sensors in this chamber. When our body moves, tilts, or sways to a side, the fluid in the chamber moves and hits certain sensors. these sensors then send the signal to our brain, which orders our body to move in opposite direction to avoid fall.

[anupmathur]

Hi up2date,
so we meet again!
I feel diappointed with your querry. I had expressed doubts earlier (do u remember?)!
This site has ALL the information you will ever need. You simply haven't bothered to read it. And you persist with your inane questions. Again please recall, I had mentioned this earlier as well!!
At least do the needful now. Yogesh and Salil etc.. have already posted excellent information on all that you are asking......Please read!!!
Sorry if this annoys you

[up2date]

You did annoy me. But thats OK. I guess you jump to conclusions quick.
My question was not completely about AMS. Its an comparison/difference between AMS and Mountain sickness. At least our group have this doubt. There are chances that people might misunderstand the difference between AMS and Mountain sickness as vomiting is symptoms in both the cases.
Googling didn't help much. So wanted to check here.

And what was inane in the query??
Sorry, if any of my comments had annoyed you.

[hitanshu]

As you'd have realized, AMS has no guarantees.

On a bike though, you have significantly less chances of hitting AMS - so i've seen.

[anupmathur]

I guess there's a difference in googling....
Here's what google threw up at my first search string:

Health encyclopaedia » A » Altitude sickness
Altitude sickness Introduction
Altitude sickness (also known as acute mountain sickness) can occur in its mildest form at around 2500m (8000ft) above sea level (common ski resort height), but is more likely to occur, and to be more severe, at higher altitudes of 3500m (11000ft)and above.
As you go higher the air still contains the normal amount of oxygen (21%), but atmospheric pressure decreases which results in each breath containing fewer molecules of oxygen. For example, at 5500m (18000ft), each breath will contain roughly half the normal amount of oxygen.
The onset and severity of symptoms, and the altitude at which they are experienced, vary according to the individual, the rate of ascent, and the amount of time spent at high altitude. In most cases symptoms develop 24-36 hours after arrival at altitude, and begin to ease within 48 hours as the body acclimatises (gets used to it).


Travel sickness Introduction
Travel sickness, or motion sickness, is when you feel sick or vomit because you’re moving. It is caused by repeated unusual movements during travelling.
This includes travel in a vehicle such as a car, plane or boat, and other activities such as fairground rides.
In these situations you are in a static (fixed) position, sitting on the ride or in the vehicle, but you can see and feel that you’re moving, whether it’s along the road, across the sea or up in the air.
Travel sickness is common. Children experience travel sickness more often than adults but often grow out of it, as they get older.

Happy journeys! And there is no evidence, even anecdotal, to link travel sickness and AMS susceptibilities.

[Yogesh Sarkar]

For a normal person motion sickness and AMS might look same at the onset; however the effects of AMS are much more profound and dangerous.

AMS isn’t going to hit you below 8-9000ft, above that it can hit you any time. Also in case of AMS the vomiting usually doesn’t occurs unless the situation gets quite worse and from what I have heard the vomiting usually happens when you are trying to sleep at the high altitude, else it is mainly headache which hits you.

[pecos]

Does high blood pressure increase chances of AMS?

[Salil]

Pecos, I think your doc will be able to answer that question better. Low atmospheric pressure would naturally increase blood pressure within our body for people who have normal blood pressure. If you already high blood pressure, then I guess it is a cause for concern.

One person I know who would be similar to you in terms of body weight would be Yogesh, the admin here I guess he would be the best suited to answer your query.

Anyway, Google found this:

The atmospheric pressure at sea level about 14.7 pounds per square inch (760 mm of mercury). Pressure at 12,000 feet (3,658 meters) is 40% less than that at sea level resulting in fewer oxygen molecules per breath (at 18,000' pressure is about 50% of that at sea level. at 29,000' it is 33% of sea level). Pulse rate and blood pressure go up sharply. Your breathing rate cannot increase enough to raise the oxygen content in the blood to sea level concentrations. The body must adjust to having less oxygen. In addition, for reasons not entirely understood, high altitude and lower air pressure causes fluid to leak from the capillaries which can cause fluid build-up in both the lungs and the brain.

source : http://www.geocities.com/dtmcbride/travel/ams.html