I. Physiological Considerations
The common cold - also known as coryza, rhinitis, and upper respiratory infection - is an acute infection of the upper respiratory tract by a filterable virus, which is then often followed by invasion of the respiratory tract by pathogenic organisms. It is considered to be highly contagious, although it is usually mild, of short duration, and endemic. The onset is marked by a chilly sensation followed by sneezing, watering of the eyes, nasal discharge, cough, and is often accompanied by a mild fever. Much has been written about this most common of all diseases.
In the Cayce readings much has also been given respecting the common cold, including a complete reading, 902-1, which is included in this File. It is an excellent commentary and worthy of study.
The balance of the body probably plays the most important part in preventing the beginning of a cold. Although Cayce stated that "it is a universal consciousness to the human body" (902-1) - yet a cold develops in the presence of an acid condition within the body and nearly always only when that condition pertains. An alkalizing effect is destructive to the cold germs themselves. The question of acidity-alkalinity is discussed in another Circulating File and seems to be a difficult concept to understand fully. Yet Cayce answered the question whether there were any special precautions to be taken against colds by the simple words, "keep alkalized." (480-45)
Whenever the fine balance of the body in its acid-base relationship is disturbed, then an individual is susceptible to a cold. Any condition - draft, wet feet, change in temperature, or any similar condition - that causes a change in circulation through affecting the body balance, the body temperature or the body equilibrium, can cause a cold if the body is susceptible. Susceptibility comes when there has been extra depletion of the vital energies of the body, which in turn produces a tendency for an excess acidity. Or, psychologically, if an individual becomes aware of a detrimental change in body temperature or environment, this uses energies and makes him thus more susceptible. Loss of sleep; excess emotional turbulence, such as anger, resentment or contention; excess activity leading to extreme tiredness - all these create either a marked depletion of the body's energies or a pouring out of poisons from the glandular system into the lymph circulation, preparing the system so that it blocks the circulation to the eliminating channels, creating again an acidity and a disturbance which predisposes to a cold.
The glands, of course, secrete according to impulse from the emotional system. With anger these secretions poison the body. "Thus you can take a bad cold from getting mad. You can get a bad cold from blessing out someone else, even if it is your wife." (849-75)
An Acid-reacting diet - such as too much of meat and starches - creates a susceptibility to colds within the body. Likewise, incorrect eating does the same thing. Food should be thoroughly masticated. "Bolting food, or swallowing it by the use of liquids produces more colds than any one activity of a diet." (808-3) 1
Overheated rooms, for instance, lessen the oxygen available which weakens the circulation of life-giving forces that destroy any germ. Tiredness, overacidity, or overalkalinity all contribute at times to the production of a cold.
Physiologically we can see that each body is indeed a law unto itself, due to the varying activities of physiological processes which are brought about by the many factors playing a part in each person's body. "Consequently, as we find, this [condition, the cold] is one of the most erratic conditions that may be considered as an ill to the human body." (902-1)
II. Rationale of Therapy
Care of the body externally is certainly one of the obvious factors in prevention. Precautions should be taken as to clothing, drafts, damp feet; one should avoid becoming overtired or too exhausted, and should avoid being in a room that is too hot or too cold. Keeping in the open air often is an excellent preventative, if one does not let the body get too cold.
A normal, alkaline-reacting diet should be kept at all times when one is exposed to colds. This means much in the way of fresh fruits, though citrus fruits and cereals should not be combined at the same meal. Green raw vegetables should be a portion of the diet. The meats should be such as lamb, fowl, fish, or the like. Occasionally the broiled steak or liver would be well. A balance is needed between the starches and proteins with adequate amounts of carbohydrates.
Above all, one should not allow himself the costly luxury of anger, resentment, hate, or argument. He should cultivate instead the quality of forgiveness, teach himself to be tolerant of his brother's mistakes and his own shortcomings, thus developing an equanimity of spirit, which is perhaps the most important prerequisite to a balanced body function.
The body must function as a unit. Thus, care of the body externally and precautions as to diet and emotion must also be combined with specific attention to what might be called therapy as a preventive. Vitamins are substances which stimulate the more normal function of the glands of the body. All vital forces in the body are activities of the glandular system, and these forces are stimulated by specific glandular activity attributed to the functioning of certain portions of the system. Thus vitamins would be helpful when one is exposed to colds. "Vitamins are not as easily overcrowded in the system as most other boosters for a general activity." (902-1) And it would be well to keep the glandular system promoting the normal vital forces within the body at times of stress.
Yet, there is a word of caution about too many vitamins either as a preventive or where infection already exists. "For, that which may be helpful may also be harmful - if misapplied - whether by the conscious activity in a body or by an unconscious activity in the assimilating forces of a system. If this were not true, there would never be an unbalancing of any portion of the functioning system; neither would there be the lack of coordination or cooperation with the various organs in their attempt to work together." (902-1)
In addition to the proper use of vitamins as a preventive in keeping the body balanced, the readings suggested that it was necessary to keep the eliminations adequate, both through the intestines and through the kidneys. Thus a cathartic or an enema in the early stages of body unbalancing would be helpful.
For purifying the kidneys, one to three drops of sweet spirits of nitre or 15 drops of onion juice is suggested. Another rather unusual therapy for prevention is the use of a mixture of equal parts of mutton tallow, spirits of camphor, and spirits of turpentine massaged into the feet and ankles and legs of an individual. Why massage the feet for an oncoming cold in the head? Perhaps the same answer could be used here as would be appropriate for the question - why is it when your feet get cold and wet that you may get a cold in the head? The body is indeed a unit.
III. Suggested Therapeutic Regimen
Because of its erratic occurrence in the course of human events and because it meets within each body a separate law of function and activity, the common cold becomes a difficult and puzzling condition to treat successfully. There are, however, certain general rules that have evolved in the readings which might prove helpful.
1. Rest is a primary factor and apparently has no substitute. This is due to the need within the body for a balanced function of the autonomic nervous system. During rest and sleep, balance of the autonomic is, to a great extent, restored. If the body is contracting a cold, something has been stressed through exhaustion, and rest is usually necessary to undo this condition.
2. Much water should be taken during these times. An alkalizer should also be added to the system, such as a teaspoon of baking soda in a glass of water or something similar. The water helps to cleanse the body and eliminate drosses, and the soda tends to produce alkalinity within the body.
3. A diet that is right (as proven over a period of time) for an individual is probably the best at these times. However, it should conform to the dietary suggestions already mentioned. For the acute phase of a cold, a liquid diet generally is best. Little meat should be taken until the recuperative stage, and certainly too much should not be eaten. For  Cayce suggested citrus fruit for two days with an occasional teaspoonful of spiritus frumenti in a large glass of lemonade.
4. Vitamins of all kinds are helpful when the body has been weakened to any degree. These supply, through boosting the glands of the body, the vital energies needed for health.
Many things in many ways are beneficial to those who have contracted cold - dependent, to be sure, upon the general constitution of the body, the amount of vitamins stored in the system, and so on. Also the response depends greatly on whether or not there is the opportunity given for rest and the not eating too much, so that the body may be aroused to gain its equilibrium.
Hence it is necessary that there be given the booster for those portions of the body needing the stimulation; and those elements that produce more of vital energies are the more helpful influences. (902-1)
5. Weaknesses which are present within the body should be recognized and corrected. This may be due to old injuries, or it may be some factor that has already been understood as being a weak, or susceptible, portion of the body functioning. Constipation is a factor which contributes to many illnesses. Assimilation may have been inadequate for a long time. These various weaknesses must be tended to.
6. Various special therapies were suggested in many instances in the readings. For , the reading suggested Sal Hepatica, three doses, two hours apart; to be followed by a half teaspoon of Castoria every hour until the digestive tract was cleared. This same individual was told to treat his fever by bathing his feet in hot water every four hours, and following this, to take a rubdown from the hips to the feet and including the feet with the combination already mentioned (equal parts of mutton tallow, spirits of turpentine, and spirits of camphor).
Such a combination was also suggested at times to be used on the throat and chest, or over the sinuses. Fume baths with rubdowns; steam cabinet treatments; massages; manipulative therapy; nose sprays and gargles with Glyco-Thymoline and Listerine alternated; a variety of cough syrups (see Appendix), such as taking the white of an egg, juice of a lemon, teaspoonful of honey, and two drops of glycerine carefully concocted - all of these are apparently helpful in various circumstances to restore the body to a normal balance.
Perhaps the most interesting specific suggestion Cayce gave followed an injunction to  to keep the body alkaline and eliminate the cold. Then he said: "Instead of snuffing, blow! Instead of resentments, love!" (288-44)
In concluding the commentary, perhaps we should remind ourselves that the body really has a capacity to function normally and we must urge it to do so without sacrificing other functions within the body.
Thus, we would administer those activities which would bring a normal reaction through these portions, stimulating them to an activity from the body itself, rather than the body becoming dependent upon supplies that are robbing portions of the system to produce activity in other portions, or the system receiving elements or chemical reactions being supplied without arousing the activity of the system itself for a more normal condition. (1968-3)
[Note: The preceding overview was written by William A. McGarey, M.D. and is excerpted from the Physician's Reference Notebook, Copyright © 1968 by the Edgar Cayce Foundation, Virginia Beach, VA.]