A portable, handheld measurement device for monitoring lung function is provided. The measurement device includes one or more components designed to directly or indirectly detect air flow properties such as the direction, flow rate, and/or volume of air flow within a lumen of the device. In some embodiments, the air flow properties are determined from changes in pressure within the lumen. The measurement device may form part of a system that includes a remote computing device and a computer server. In some such embodiments, at least one of the computers present within the system calculates spirometry measurements from the air flow detected within the measurement device. Such measurements may be stored, displayed, and/or shared with others. Various methods performed by the devices and systems are also disclosed.
