Biological systems pose particularly challenging measurement issues. This is partly because the biological domain is characterized by complexity and diversity. As a consequence, the results of measuring biological organisms will often result in a distribution of values. A further complication in medicine is that much measurement is of attributes or characteristics relating to internal or subjective phenomena such as of pain, anxiety, and dizziness. ‘Measurement in the life sciences, medicine, and health’ considers the scope of medical measurement, how to measure patients, and how to measure the health of populations. In modern medicine, there are many different reasons for taking a measurement, and hence many different types of measurement.