We often hear someone telling that he is sensitive to cold, catches cold easily or get fever frequently. This speaks about the susceptibility of the individual. Susceptibility is considered as the state or fact of being likely or liable to be influenced or harmed by certain things. It is the vulnerability or sensitivity of an individual to get diseases. Susceptibility speaks about the defensive mechanism in the human body. It is the state of being predisposed to, sensitive to or of lacking the ability to resist a pathogen, familial disease or a drug. When there is susceptibility, that individual is easily affected, influenced or harmed by something. The general capability of the organism to receive impression or the power of the organism to react to stimuli is determined by susceptibility. It is one of the fundamental attributes of life.
Types of susceptibilityIn Homeopathy, susceptibility is one of the important concepts on causation of diseases and remedy reaction. Even though the term susceptibility is not directly referred in Organon of Medicine by Dr Hahnemann, Dr James Tyler Kent in his Lectures on Homeopathic Philosophy, quotes aphorisms (§) 30,31,32,33 in Organon to explain the concept of susceptibility. Further, H.A. Roberts defines susceptibility as the expression of vacuum in the individual. The vacuum attracts and pulls for the things most needed that are in the same plane of vibration as the want of the body. Primarily susceptibility is the reaction of the body to external and internal influences. Dr Stuart M. Close defines susceptibility as the general quality or capability of the living organism to receive impressions and the power to react to stimuli.
Natural susceptibility or normal susceptibility
There is an innate ability of the organism to react defensively to a toxin, a contagion or an infection and to react constructively to food and drinks. This is called immunity. Human body is protected from the external influences like pathogens or changes in routines due to this immune response. When the immunity is reduced or the immune mechanism is deranged, the person become sensitive and get easily sick. However, there is a natural susceptibility in every living organism to protect it from harmful effects of substances that we use on routine life. For example, when we peel onion, it irritates eye producing watering and burning, running nose and so on. This is a natural response of the body to protect the body. Like this when one is exposed to smoke or dust, some irritation or discomfort is experienced and the moment, we come out to open air, we feel normal. This is natural susceptibility or normal susceptibility.
Kent speaks of artificial susceptibility in his Lecture of Homoeopathic Philosophy. When medicines are given they act for a time satisfying the susceptibility. They alter the susceptibility and when that dose of medicine is no longer able to act on altered susceptibility another dose or potency is required. This altered susceptibility that is arrived at is called artificial susceptibility.
Susceptibility may become morbid and perverted under conditions of disease, suffering and death. According to S.Close morbid susceptibility could be regarded as a state of negative or minus condition-a state of lowered resistance.
Abnormal or Altered susceptibility
Abnormal susceptibility either demands excessive or defective stimuli or reacts to stimuli in an exaggerated or a diminished way.
In Homeopathy susceptibility is considered as the general quality or capability of the living organism of receiving impressions; the power to react to stimuli. The cure and improvement of diseases depend upon the power of the organism to react to the impression of the curative remedy. When a well selected medicine is administered to a sick person, the disappearance of the symptoms and restoration of the patient to health represents the reaction of the susceptible organism to the impression of the curative remedy.
The “homœopathic aggravation," is also the reaction of the organism of lowered susceptibility, as it responds to the gently stimulating action of the medicine. It is understood that action and reaction in the medical and physiological sense takes place only in the living organism, and that it depends upon that fundamental quality and attribute of life which we call susceptibility. We shall see that the kind and degree of reaction to medicines depends upon the degree of susceptibility of the patient, and that the kind and degree of susceptibility, in any particular case or patient, depends largely upon how the case is handled by the physician; for it is in his power to modify susceptibility. Indeed, this power to modify susceptibility is the basis of the art of the physician.
According to H.A.Roberts -Reaction to stimuli under the healthy state of the individual could be recognized by the reaction of the individual to physical environment, food, remedies and its defense to toxic agents. Health of the individual depends on this normal susceptibility. We must also predicate a state of normal susceptibility to remedial as well as toxic agencies, which it is the duty of the physician to conserve and utilize. No agent or procedure should be used as a therapeutic measure which has the power to diminish, break down or destroy the normal susceptibility or reactibility of the organism, because that is one of the most valuable medical assets we possess.
Dr Stuart M. Close says “If the physician knows how to modify susceptibility in such a way as to satisfy the requirements of the sick organism and bring about a true cure, then is he a physician indeed; since cure consists simply in satisfying the morbid susceptibility of the organism and putting an end to the influx of disease-producing causes. To accomplish this he must know that susceptibility implies and includes affinity, attraction, desire, hunger, need; that these all exist and express themselves normally as states and conditions in every living being; but that they may become morbid and perverted and so cause disease, suffering and death. He knows also that susceptibility implies the existence of the wherewithal to satisfy susceptibility; to supply need, hunger, desire, affinity, attraction, and he knows how and where to find the necessary modifying agents.”
It is a well-known fact that the living organism is much more susceptible to homogeneous or similar stimuli than to heterogeneous or dissimilar stimuli. Throughout the entire vegetable and animal kingdom we find the law of development and growth to be like appropriating like. Organism and organs select elements most similar to their own elements. The same law holds good in excretion, each organ excreting or throwing off elements analogous to those of its, own basis structure.
So it is in satisfying the morbid susceptibility which constitutes disease. As hunger demands food, so disease demands medicine. But the demand is always consistent with the universal law. It is for the symptomatically similar medicine, because that is the only thing that really satisfies the susceptibility.
This morbid susceptibility which constitutes disease may exist toward several different medicines, the degree of susceptibility to each depending upon the degree of symptom similarity; but the highest degree of susceptibility exists toward the most similar - the simillimum, or equal. Hence, a given patient may be cured of his disease homœopathically by either of two methods; by giving several more or less similar medicines in succession, or by giving one exactly similar medicine--the similimum or equal. It depends upon whether he is being treated by a bungler or an expert. The bungler may "zig zag" his patient along through a protracted illness and finally get him well, where an expert would cure him by the straight route with a single remedy in half the time.
Factors which modify susceptibility
Age: – Susceptibility is greatest in young vigorous persons and children and it diminishes with age. Children are particularly sensitive during their developmental period. The most sensitive organs are those, which are being developed.
Constitution and temperament: – High potencies are adapted to nervous, sanguine and choleric temperament and also to intelligent, intellectual, zealous and impulsive persons who are quick to act and react. Lower potencies and more frequent dose correspond to torpid, phlegmatic individuals, coarse fibered, sluggish individuals of gross habits and to those of great muscular power who require powerful stimuli to excite them.
Habit and environment: – Susceptibility is increased by intellectual occupation, by excitement of imagination and emotions, by sedentary occupation by long sleep and effeminate life. Therefore high potencies are required. A person who is accustomed to long and severe labor out of doors who sleep little and whose food is coarse is less susceptible. Persons expose to continuous influence of drugs such as tobacco worker and dealers, distillers and brewers and all connected with liquors and tobacco trade, druggist, perfumers, chemical workers are less susceptible and require low potencies. Mentally less alert require low potencies. Persons who have taken many crude drugs of allopathic, homoeopathic or bargain counter prescription often require high potencies for their cure.
Pathological conditions: – In certain terminal conditions the power of organism to react even to indicated homoeopathic remedy is low therefore material doses are required. This may be due to existence and gross pathological lesions, long existent exhausting chronic disease or much previous treatment. If the grade of disease is low, power of reaction is low; the remedy must be given low.
Seat character and intensity of the disease: In certain rapidly fatal diseases like cholera, susceptibility is low so it requires material doses or low potencies. Diseases characterized by diminished vital action, torpor, collapse require lower potencies and increased vital action requires high potencies.
Previous abuse of medicine: – Due to this we may find that the patient is not at all sensitive even to the indicated remedy. Then the medication has to be stoped for few days, regulate the diet and regimen. Hahnemann recommends the administration of opium in one of the lowest potencies every 8th or 12th hour until some signs of reaction are perceptible. By this means, susceptibility is increased and new symptoms of disease are brought to light. Carbo veg, Sulphur and Thuja are other remedies, which serve to arouse the organism to reaction so that indicated remedies will act.
Dr Stuart M. Close, The Genius of Homeopathy, Lectures and Essays on Homeopathic Philosophy
J.T.Kent, Lectures on Homoeopathic philosophy
H.A.Roberts, The Principles and Art of cure by Homoeopathy