Embodiments of the invention relate to a method for detecting the critical situation of a subject that comprises measuring a physiological parameter of the subject. The method includes (a) measuring the physiological parameter; (b) calculating a variation rate of the physiological parameter; (c) determining a synthesis variable for the physiological parameter by taking into account both the value of the parameter and the variation rate thereof; and (d) detecting a critical situation from the synthesis variable. Steps (a) to (c) may be implemented for at least two physiological parameters, and the method may further include determining a global decision variable from the different synthesis variables, the critical situation being detected during step (d) from the global decision variable. Embodiments of the invention can be used for improving the detection of accidents or health problems, particularly for the elderly at their places of residence.