Human odor, which results from internal hormonal or metabolic changes, contains biomarkers for certain diseases and reflects the physiological status of an individual. The major sources of human odor are breath, saliva, sweat, skin and urine. Recently, the components of exhaled breath, skin emissions and urine odor have attracted attention as diagnostic biomarkers of diseases and disorders, such as diabetes, liver disease, asthma, lung cancer and chronic obstructive pulmonary disease and cystic fibrosis.