Susceptibility is the general quality or property of a living organism to react to the stimuli in response to stimuli's impression.

Susceptibility is one of the most important and essential properties of life. Both physiological and pathological activities that take place in a living organism is because of this property of reacting to the stimuli.

As no two individuals are similar, so does the susceptibility of the two individuals. Some persons easily succumb to the sudden climatic changes, whereas others are least influenced. In the same manner, some individuals and races are more susceptible to some infections than others. In case of hypersensitivity some individual develops severe reaction on coming in contact with some substances. This is because of the morbid susceptibility of the individual and underlying miasmatic influence.

It is because of reaction of susceptible organism to the impression of the homoeopathically selected remedy that the disappearance of symptoms takes place to effect a perfect cure. The action of the administered medicine and the response or reaction shown by the patient to the medicine depends on this quality of susceptibility. This degree of susceptibility can be modified by the physician, which he can do by application of appropriate potentized homoeopathic remedy. The process of cure involves nothing but removal of morbific susceptibility of organism to the influx of disease producing morbific agents. The susceptibility of diseased individual to the medicine depends upon the degree of symptom similarity. The more the medicine similar to the totality, more susceptible the patient is to the given medicine. Hence more easily will his malady be removed.

The symptoms produced by a healthy person during proving reflects his susceptibility, as the symptoms are produced in response to stimuli of the drug substance. The more the symptoms are produced the more he is susceptible to the medicine. The more important he is as a prover as more number of symptoms are recorded to get perfect drug picture, so as to employ it in a sick individual for restoration of health.

Susceptibility is a God gifted quality of an organism. It should not be altered or destroyed. It protects the organism from the harmful morbific agents, and defends from various diseases by producing antibodies, leucocytes and antitoxins. When the power of organism to react to the stimuli is destroyed or altered, it cannot defend itself from the harmful influence of external morbific agents like toxins, bacterias etc. It cannot even carry out its normal physiological activities like metabolism, digestion etc. The recently employed methods like passive immunization and antibiotic treatments reduce the susceptibility property of the human beings, thereby making them more helpless to defend to the attacks of diseases.

The only way we can restore the morbid susceptible condition during disease without destroying it, and also making the organism more stronger to defend the harmful external influences, is by appropriate employment of the homoeopathic medicine.