We have already conducted a number of studies (and published in medical journals) suggesting that brain natriuretic peptide (BNP) levels may rise with altitude illness. This would be useful as a way of allowing doctors to make a decision about whether or not someone with signs of illness at altitude actually has altitude illness and therefore would benefit from removal to lower altitudes or has some other problem (such as a viral illness). There is a good reason why BNP may be useful in that it rises if the heart is working hard against higher blood pressures in the lungs. This is the principle mechanism in one form of potentially fatal high altitude illness (high altitude pulmonary oedema).
In this study we will only investigate team members who ask to see one of the expedition doctors who will then perform a full examination, make a diagnosis but also check a BNP reading, from a blood sample on a fully portable system we will carry with us in Nepal.