Systems and methods for analyzing multiple components of a fluid sample are provided. In certain embodiments, a system can include an analyte detection system configured to measure first analyte data in a first component of a fluid sample received from a patient and measure second analyte data in a second component of a fluid sample. In some embodiments, one or more portions of an optical system is movable with respect to other portions of the system in order to optically and/or electrochemically analyze multiple components of a fluid sample. In other embodiments, optical and/or electrochemical analysis can be performed simultaneously on multiple components of a fluid sample. In some embodiments, a first analyte can be measured in a sample (e.g., whole blood) before the sample is separated into its components (e.g., plasma, red blood cells, etc.), and a second analyte can be measured in a component of the sample after separation.