The present invention provides biomarkers for sensitive, specific, accurate and quantitative diagnosis and assessment of chronic hypoxia. In particular, the present invention provides 2-hydroxyglutarate as a biomarker that is differentially produced in chronic hypoxia. Furthermore, embodiments of the invention are able to differentiate between chronic and acute hypoxia. Assays for levels of 2-hydroxyglutarate may be used alone or in conjunction with additional biomarkers of hypoxia to increase the precision of analysis. In particular embodiments of the invention, the level of 2-hydroxyglutarate and at least one second biomarker may be assayed to generate a hypoxic profile that can be compared to a reference or control profile, thereby diagnosing a subject as normoxic, chronically hypoxic, or acutely hypoxic.