Marker compounds indicative of variations in physiological conditions, genetic defects or disease states have been found to be present in apocrine sweat and, in many conditions, these markers are present in apocrine sweat in elevated levels when compared to blood. These markers are collected and/or detected in apocrine sweat and used as an indicator that a disease state or particular physiological condition exists. A skin patch, wipe or electronic detector for vapors released from apocrine sweat are used to indicate the existence of a disease state or changing physiological condition. The patch or wipe can include in monoclonal antibodies or other chemical compounds that can indicate the presence of specific markers. This may include indicators that render visible, the existence of a reaction between the monoclonal antibody or chemical compound and the marker compound to indicate the existence of the condition being tested for. Various different disease states can be detected including, but not limited to heart disease, cancer, autoimmune disease, viral or bacterial disease, renal disease, drug intoxication and other systemic illnesses. Fertility for conception and histocompatibility for organ transplantation of individuals should also be detectable.