Take the 2-minute tour ×
The Great Outdoors Stack Exchange is a question and answer site for people who love outdoor activities, excursions, and outdoorsmanship. It's 100% free, no registration required.

This question in some ways is related to this question asked by JollySin.

When I did my first Himalayan trek, my guide there had told me that those with a low blood pressure (BP) are more susceptible to Acute Mountain Sickness (AMS). The logic according to him was that low BP along with high altitude will result in the blood flow to the brain reducing further and the symptoms of AMS are more likely to occur at an earlier stage in those with a low BP.

Hence, is there a scientific relationship between BP(either low or high) and AMS?

Please try to include references for the answers.

share|improve this question

3 Answers 3

up vote 5 down vote accepted

There is no documented scientific relationship between individual blood pressure and AMS. Furthermore, your guide appears to be completely mis-informed as to the mechanics of AMS. The most common symptom of AMS - a roaring headache - is caused by swelling of the brain as the body attempts to make up for reduced oxygen in the blood by pumping harder and faster (hence an increased heart rate). See: http://www.altitudemedicine.org/index.php/altitude-medicine/learn-about-altitude-sickness

Incidentally, high blood pressure would put one at risk for cardiac arrest, not AMS, when travelling quickly to high altitudes. See: http://www.altituderesearch.org/traveling-to-altitude/113

share|improve this answer
3  
The possibility of brain getting less oxygen due to low blood pressure seems possible. Why completely rubbish his claim? If thought from a common sense perspective, it looks feasible that someone with low BP might face symptoms early. I might be wrong. Pardon me if I am. –  Unsung Dec 20 '13 at 17:55
    
I appreciate the common sense aspect of it - I get it - but you asked if there was a scientific relationship between BP and AMS. I dispute the possibility that low blood pressure makes one more susceptible to AMS because the key factor is the oxygen saturation level in the blood, which is not related to blood pressure. –  Andrew Dec 22 '13 at 23:21
1  
@Andrew: ...because the key factor is the oxygen saturation level in the blood, which is not related to blood pressure. This statement of yours, Do you think that Human Cardiovascular system is so simple and straight forward to understand? –  WedaPashi Jan 7 at 6:01

There are a few things that I discussed with a quite a few mountaineers over the years and also have subtle amount of reading about AMS. Scientifically, this happens:

  • As you gain altitude, in Death zones, the amount of Oxygen in the air decreases. This in turn causes the blood to get more delated, further imbalancing the blood pressure.
  • These imbalances in the blood pressure are not sustainable by heart, which is already panting.
  • As, this blood reaches the Cerebrum (a part that constitutes majority of what we call brain), it causes the thin lines that carries blood, to get swollen. At this stage, you get heavy head-aches.
  • If tolerated they go on to leak.
  • This leaking is really a dangerous stage where you start hallucinating, blurry vision, hearing the things. Its just because when it leaks, it starts spreading across the brain and causing the Cerebellum to swell.

Now, you must be saying where does the Blood Pressure play part in it? The lower the blood pressure, the lower is your VO2. VO2 is what indirectly decides when your heart starts panting, and how much to exert your lungs.

share|improve this answer
1  
Sorry, but this is confusing, and - more importantly - inaccurate. VO2 Max is not determined by blood pressure. Period. See livestrong.com/article/79469-relationship-between-heart-rate- –  Andrew Dec 29 '13 at 5:49
    
@Andrew: The lower the blood pressure, the lower is your VO2 This does not directly mean to be determining factor. But if you can see that, Vo2(max) = 15.3*((MHR)/(RHR)), you would be able to indirectly relate the blood pressure with your Heart Rate. Get your facts cleared! –  WedaPashi Dec 31 '13 at 11:01
1  
@WedaPashi My question doesn't refer to the death zone (8000+ meters). It's just about AMS on altitude gain. –  Unsung Jan 10 at 19:37
1  
@WedaPashi the USOP estimation formula you cite is indeed an acceptable substitution for the Fick calculation of VO2 Max, but MHR over RHR does not indicate blood pressure. Your logic would suggest that an individual with high blood pressure gets more oxygen to his/her organs and muscles and is therefore less likely to develop AMS. Please refer to any source that supports the idea that blood pressure and AMS have any correlation, or that blood pressure is related to blood oxygenation. –  Andrew Jan 18 at 4:50
    
@andrew: Okay mate, google Chronic Mountain Sickness and HACE –  WedaPashi Aug 4 at 5:41

I would think not. AMS is caused by lower atmospheric pressure which in turn reduces the number of O2 molecules you get to breathe in. Your own personal blood pressure has nothing to do with the number of O2 molecules available to breathe.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.