Dr Kellogg says...
A good blood supply is like a travelling physician...it repairs injuries by the same marvellous methods by which it builds up and maintains the body in health - through normal nutritive process.
Recovery from diseased conditions is effected by means of the cell and tissue activities by which the ordinary functions of the body are maintained. p242
The blood is the great healer. In the words of Holy Writ, "the blood is the Life." It washes out of the tissues the waste and toxic products which they contain, and brings new vitalizing and energising elements to take their place. The only way in which a diseased organ can be restored to permanent health is by complete renovation in its tissues, since function depends on structure. This requires a tearing down and a rebuilding through increased movement of blood and lymph. p242
All hydrotherapy aims to cause one, or all, of the following three reactions in the body Locally (in one part) or Generally (the whole body),
- Thermic Reaction - increased heat and increased METABOLISM within cells and more generally such as increased healing, digestion or phagocytosis
- Circulatory Reaction - increased blood and lymph flow
- Nervous-system Reaction - feeling refreshed and energetic.
The reactions mentioned above are the Excitant, Tonic or Stimulating effects. If we wanted Sedative, Depressing effects we would aim for, decreased metabolism, or blood flow, or feeling sedated, pain-relief and sleepy.
Both heat and cold will produce Excitant or Sedative effects depending on the length of time it is applied and whether it is the Intrinsic effect of the heat or cold, or the Reactionary effect as the body responds to the heat or cold.
- The Intrinsic effect is the result of the action of the heat or cold itself - Heat is Excitant, Cold is Sedative.
- The Reactionary effect is a series of changes set in motion by the body to counteract or overbalance the Intrinsic effect of the heat or cold. The Reactionary effect of Heat is Sedative, Cold is Excitant.
So in practice, to achieve an Excitant effects we use,
- Short Heat - intrinsic effect (feel refreshed after a quick hot shower)
- Short Cold - reactionary effect (feel refreshed after a quick cold shower, or Cold-Mitten Friction)
To achieve a Sedative effect we use,
- Long Heat - reactionary effect (feel sleepy after long hot bath)
- Long Cold - intrinsic effect (pain relief after an ice pack)
Normally the Thermic, Circulatory and Nervous-system Reactions occur simultaneously but with careful management of the treatment it is possible to reinforce one of the reactions and suppress the others. The most important occasion is when there is a painful local inflammation, ie. there is already an overactive metabolism and overstimulated pain nerves. To relieve the local congestion of the inflammation we need to increase just blood and lymph flow. This is achieved by a single short hot then a very short cold application that withdraws all the heat added. This is called a Revulsive treatment.