Method for achieving characterization of a blood pressure of a user, comprising the following steps: - a) placing an optical device on a limb of the user, the optical device comprising: • a light source, arranged to emit light towards the limb; • a photodetector, the photodetector being arranged to detect an intensity of light emitted by the light source and having propagated through the limb; - b) applying compression to the limb of the user, the compression being exerted between the heart of the individual and the optical device, such that a pressure ( P ( t)) is applied to the limb for a compression duration (Δt), the compression duration comprising: • a phase of inflation, in which the applied pressure increases; • a phase of deflation, in which the applied pressure decreases; - c) during the compression duration (Δt), illuminating the limb with the light source and measuring an intensity detected by the photodetector at various times, so as to obtain a time-dependent function ( I ( t)) corresponding to a variation as a function of time in the intensity during the compression duration, the method being characterized in that: - d) low-pass filtering is applied to the time-dependent function ( I ( t)), so as to extract a low-frequency component ( I DC (t)) from the time-dependent function ( I ( t)), the low-pass filtering being carried out with a cut-off frequency strictly lower than a heart rate of the individual; - e) from a time determined from the low-frequency component ( I DC (t)), the blood pressure of the individual is characterized depending on the pressure applied at said time. - a) placing an optical device on a limb of the user, the optical device comprising: • a light source, arranged to emit light towards the limb; • a photodetector, the photodetector being arranged to detect an intensity of light emitted by the light source and having propagated through the limb; • a light source, arranged to emit light towards the limb; • a photodetector, the photodetector being arranged to detect an intensity of light emitted by the light source and having propagated through the limb; - b) applying compression to the limb of the user, the compression being exerted between the heart of the individual and the optical device, such that a pressure ( P ( t)) is applied to the limb for a compression duration (Δt), the compression duration comprising: • a phase of inflation, in which the applied pressure increases; • a phase of deflation, in which the applied pressure decreases; • a phase of inflation, in which the applied pressure increases; • a phase of deflation, in which the applied pressure decreases; - c) during the compression duration (Δt), illuminating the limb with the light source and measuring an intensity detected by the photodetector at various times, so as to obtain a time-dependent function ( I ( t)) corresponding to a variation as a function of time in the intensity during the compression duration, the method being characterized in that: - d) low-pass filtering is applied to the time-dependent function ( I ( t)), so as to extract a low-frequency component ( I DC (t)) from the time-dependent function ( I ( t)), the low-pass filtering being carried out with a cut-off frequency strictly lower than a heart rate of the individual; - e) from a time determined from the low-frequency component ( I DC (t)), the blood pressure of the individual is characterized depending on the pressure applied at said time.