There are four major applications of GIS in health geography: spatial epidemiology, environmental hazards, modelling health services, and identifying health inequalities. This lecture went more in depth on spatial epidemiology which examines the spatial variations in various disease risks. In general, small areas are used for epidemiological studies as they can include less confounding factors, which in turn can give more accurate explanations for found correlations. Common issues in epidemiological studies include the misalignment of spatial units and uncertainties related to the quality, compatibility, and availability of data points.

GIS for environmental hazards is used to determine their causes as well as possible mitigation factors. Modelling health services and identifying health inequalities are closely related in health geography. Often health inequalities become the determining factors for modelling health service distributions.

Epidemiology can be divided into that focusing on health and the importance of location in determining it, and disease and how one is identified. Identifying a disease can be difficult, so in order to study it we have to be able to measure its occurrence.  Some common measures include counts, prevalence, incidence and mortality.