Abstract: A method for detecting disease in a patient includes providing infrared (IR) light and coupling the IR light through direct lens coupling or through a first group of one or more optical fibers. IR light is reflected from a portion of the patient and collected by a lens arrangement or a second group of one or more optical fibers. The reflected IR light is dispersed into its spectrum which is detected and analyzed. An apparatus suitable for diagnosing a disease in a patient includes an IR light source and optical fiber or direct lens coupling of IR light onto a body part or fluid of the patient. Reflected light from the patient is optically dispersed using a prism or grating. An IR focal plane array receives the optically dispersed light. The spectrum of the reflected IR light is used to provide a diagnosis of disease in the patient by identifying various disease markers or chemical fingerprints. The method and apparatus are capable of non-invasively detecting disease markers in a patient.