The effects of altitude on our body
1 min
Did you know?
In a previous post we talked about the disorders related to exposing our body to very low temperatures and the risks we may face.
Today, instead, we want to talk to you about the effects of altitude on our body*, which can occur particularly in people who take part in mountain activities such as mountaineering.
As altitude increases, one consequence is the fall in atmospheric pressure, which causes a rapid drop in the percentage saturation of Hb (haemoglobin) in arterial blood.
People who climb quickly to altitudes of 3000 m or higher may experience the symptoms ofhypobaropathy, or altitude sickness. This is due to the increased ventilatory drive to obtain more O2 (oxygen), which causes respiratory alkalosis because CO2 (carbon dioxide) is exhaled faster than it is produced.
The symptoms of altitude sickness include nausea, fatigue, loss of appetite, tachycardia, laboured breathing and nervous dysfunction, characterised by impaired judgement, lack of coordination and dizziness.
These effects are well known to mountaineers, which is why anyone preparing, for example, to climb one of the legendary Himalayan peaks plans a period of acclimatisation.
Acclimatisation is necessary for people who are not used to living at certain altitudes, but there are millions of people who live at altitudes above 3000 m all year round (e.g. some villages in the Andes are located above 4800 m).
How can this be explained? How do they survive?
Our body puts in place compensatory measures that develop slowly, after the individual has spent a long period at high altitude, but that allow adequate tissue oxygenation and restore the acid-base balance.
However, these mechanisms can also have side effects, since the greater number of red blood cells increases the viscosity of the blood and therefore its resistance to flow. As a result, the heart is forced to work harder to pump blood through the blood vessels.
*source: "Fondamenti di fisiologia umana" by Lauralee Sherwood.
In a previous post we talked about the disorders related to exposing our body to very low temperatures and the risks we may face.
Today, instead, we want to talk to you about the effects of altitude on our body*, which can occur particularly in people who take part in mountain activities such as mountaineering.
As altitude increases, one consequence is the fall in atmospheric pressure, which causes a rapid drop in the percentage saturation of Hb (haemoglobin) in arterial blood.
People who climb quickly to altitudes of 3000 m or higher may experience the symptoms ofhypobaropathy, or altitude sickness. This is due to the increased ventilatory drive to obtain more O2 (oxygen), which causes respiratory alkalosis because CO2 (carbon dioxide) is exhaled faster than it is produced.
The symptoms of altitude sickness include nausea, fatigue, loss of appetite, tachycardia, laboured breathing and nervous dysfunction, characterised by impaired judgement, lack of coordination and dizziness.
These effects are well known to mountaineers, which is why anyone preparing, for example, to climb one of the legendary Himalayan peaks plans a period of acclimatisation.
Acclimatisation is necessary for people who are not used to living at certain altitudes, but there are millions of people who live at altitudes above 3000 m all year round (e.g. some villages in the Andes are located above 4800 m).
How can this be explained? How do they survive?
Our body puts in place compensatory measures that develop slowly, after the individual has spent a long period at high altitude, but that allow adequate tissue oxygenation and restore the acid-base balance.
However, these mechanisms can also have side effects, since the greater number of red blood cells increases the viscosity of the blood and therefore its resistance to flow. As a result, the heart is forced to work harder to pump blood through the blood vessels.
*source: "Fondamenti di fisiologia umana" by Lauralee Sherwood.
