A wearable device is provided having multiple sensors configured to detect and measure different parameters of interest. The wearable device includes at least one monolithic integrated multi-sensor (MIMS) device. The MIMS device comprises at least two sensors of different types formed on a common semiconductor substrate. For example, the MIMS device can comprise an indirect sensor and a direct sensor. The wearable device couples a first parameter to be measured directly to the direct sensor. Conversely, the wearable device can couple a second parameter to be measured to the indirect sensor indirectly. Other sensors can be added to the wearable device by stacking a sensor to the MIMS device or to another substrate coupled to the MIMS device.