There is provided an apparatus (100) for determining a blood pressure measurement for a subject (102). The apparatus (100) comprises a processor (104) configured to acquire, from a light sensor (106), measurements of an intensity of light (108) of a first wavelength range reflected from the skin (110) of the subject (102) for a range of forces at which the light sensor (106) is applied to the skin (110) of the subject (102). The processor (104) is also configured to analyze the acquired measurements of light intensity of the first wavelength range to identify an inflection point for the light intensity and determine a blood pressure measurement for the subject (102) based on the force at which the light sensor (106) is applied to the skin (110) at the identified inflection point.
