Since the ancient times, cryotherapy was practiced by Hippocrates, Avicenna, Galen and many other doctors and healers. However, regardless of the early experience related to using coldness for medicinal purposes, the mechanism of its effect has been explained with details in the second half of the twentieth century.
Cryotherapy is one of the oldest physiotherapeutic methods, as are heat therapy, or thermotherapy. In fact, cryotherapy encompasses a synthesis of healing medicinal methods based on applying low temperatures so that the tissue, the organs and the entire organism cool off (in Greek, kryos means coldness; therapy-healing). Since different authors have different theories about temperature, there is not a generally accepted definition of cryotherapy. Furthermore, the physiological effects of this kind of therapy are numerous: pain relieving, relaxation, anti-inflammatory properties; and it is used against swellings and varicose veins, since it narrows the blood vessels.
According to available data, cryotherapy increases the medicinal effect of products used for different kinds of inflammations. The mechanism of the effect from cryotherapy can be explained on the basis of thermoregulation. In fact, the essence is to maintain a constant inner body temperature, same in the relaxation period and in the time of a physical movement. The central and peripheral thermo receptors, sensitive to hot and cold, as well as the nervous fibers connected to the center for regulation found in the hypothalamus, enable the very process. Moreover, the receptors are sensitive even to the slightest change of temperature. The center of the hypothalamus coordinates the information received from the receptors with regulatory effect of significant organs. The skin is also an organ in which the blood flow is not related to local metabolic needs.
Supplying the epidermis with blood is bound by thermoregulation. On an experimental and clinical level, temperature limitations and phases in blood vessels reaction that occur during cryotherapy have been established.
The first phase in the reaction is vasoconstriction or narrowing of the blood vessels which characterizes with paleness and “goose” skin; pain and numbness in the place being treated. When the skin temperature lowers down to 15 degrees Celsius, the other phase begins i.e. vasodilatation or spreading of the blood vessels. This phase is characterized by a sense of heat, redness and increased skin temperature, decreased swellings, pain and inflammations. During the second phase, the organism heals, since the level of all biologically active substances is increased, including opioid peptides, neuromediators, hormones and anti-inflammatory cytokines. Additionally, in the second phase, the lymphatic and venous circulations are significantly bettered, which contributes to the active removal of metabolic products and parts of damaged cells. Also, a cold tolerance is created which points out to an increased non-specific resistance.
Cryotherapy has an analgesic effect since when the skin temperature lowers down to 15 degrees Celsius there is a decrease of the level of nerve sensitivity. Coldness sensitivity is diametrically related to the level of myelination of the nervous fibers which transmit the pain information. Besides, the movement of quick neurons is lowered with coldness, and muscle relaxation follows. Actually, coldness lowers the muscle contraction and the overall nerves-muscle tension. By decreasing the temperature in a specific area, the metabolism in the tissue slows down and decreases the need for oxygen which usually causes an increased membrane permeability and interstitial liquid absorption (water in between the cells). Nowadays, cryotherapy includes both natural as well artificial coldness sources.
Natural methods with cold sources are: higher organism resistance with cold air exposure, baths with cold water, walking on snow, applying ice on certain areas or body wrapping in cold compresses, chloroetheylene spray, soaking parts of or the entire body in a bathtub filled with water and ice. The use of climate conditions is one of the methods for body strengthening combined with previously designed trainings so that the body and tissue resistance from harmful influences increases. Therefore, in order for the entire organism to strengthen, physical factors are needed i.e. repetition during a longer period of time. Thanks to the repetition, conditioned-reflex relations develop between the irritants and the physiological mechanisms of the functional systems which are activated, so that they can adapt to the changing conditions. In relation to the time period, it needs not to be too long so that overloading is avoided. The frequent, shorter irritations are more efficient than long-term, but rare ones. Furthermore, you need to keep up with the principal of gradual intensifying of the irritator’s effect. Thanks to this, the organism will react less violently then it did in the beginning of the procedure when it had been exposed to weaker irritators. Moreover, it is crucial to subject those parts of the body, which are usually covered with clothes to cold so that they become more sensitive to the effects from changeable outer factors, as a consequence of unpreparedness of the skin receptors. An individual approach is needed when you are to establish the regime of organism strengthening procedure. For example, sex, age, physical development, possible diseases. Depending on the amount of the equivalent- efficient air temperatures, air baths are divided into: cold (less than 9 degrees Celsius), moderately cold (9-16 degrees Celsius), indifferent (17-20 degrees Celsius) and hot (23 degrees Celsius and more). Cold and chilly baths have an irritating effect which causes intensifying of all organism functions. In order to avoid a cold, chilly baths are combined with physical exercises of middle intensity. The lower the temperature, the more intensive the physical exercise must be.
The physical properties of water, primarily its heat capacity, make the water a stronger factor for strengthening of the organism than air. The widely used method for higher resistance is showering and rubbing with water. Everyone can strengthen his/her organism at any period of the year, whereas in people with chronic diseases (especially the inflammatory ones), the treatments in the summer period are recommended. For people with chronic diseases of the respiratory system, the most efficient method is feet bath (since the feet are a reflexogenic area of the upper airways). The recommended temperature is 20 degrees Celsius for beginners, by lowering it every 2-3 days for 1 or 2 degrees (until you reach 10-15 degrees Celsius). The most intensive body strengthening, which influences the immunity as well, is swimming in the winter in an open space. Before the swimming, you need to employ physical exercises and never stay in the water longer than 0, 5 to 3 minutes. And, after the swimming you have to intensively rub your body with a dry cloth and dress up immediately. A significant element in the process of strengthening of the organism with natural cryotherepeautic factors is professional supervision as well as self-control.
Nowadays, there is more interest in artificial methods of cryotherapy, than in natural ones. The reason is the fact that in the second half of the 20th century, an intensified development and production of devices for cryotherapy had begun. One of the first ones was a device whose effect was based on thermo electricity. With the help of this device, precise low temperatures can be achieved in a short period (to 20 degrees Celsius) or longer effects with mild, low temperatures (from 4 to 0 degrees Celsius). However, the flaw of these devices is in the capacity for cooling, small coldness reserves, and methodological flaws such as small amplitude of the cold inductor, etc. The most popular devices for local cryotherapy in that period were the gels in a temperature from -10 to -20 degrees Celsius. But, there are flaws such as bad dosage of the cooling process, as well as danger from frostbite. At the end of the 70 years of the 20th century, one Japanese scientist proved the healing power of short term exposure to extreme cold of a certain body part when it comes to rheumatism. Parallel with the Japanese specialists, in Germany, under the lead of the professor Fricke, numerous experiments and studies dedicated to cryotherapy were conducted. The German biologists and doctors came to the conclusion that the best agents for cooling are ice (0, 5 degrees Celsius), liquid nitrogen (-196 degrees Celsius) and dry air (-30 degrees Celsius). In fact, the dry cooled air does not provoke a sharp change of the temperature in the tissues and this is why it has a more prominent therapeutic effect. Actually, the advantage of air therapy is the ability to watch its effect, so if some pathological reactions appear, the treatment could be stopped. Pathological reactions include white skin stains, as well bruises and irritability.
Cryotherapy treatment with the help of a device has a lot of benefits. For example, the atmospheric air makes the entire process harmless and environmentally friendly; short-lasting treatment from 3 to 10 seconds to 10 minutes which does not only exclude any possibility of frostbite, but allows treating a bigger number of patients.
Because of the proved results from the cryotherapy and the little number of contraindications, this method can be applied in rheumatology, neurology, traumatology, orthopedics, surgery, dermatology, sports medicine, etc. Moreover, cryotherapy is also used in cosmetology, fitness and wellness since it revitalizes the body, stimulates substance exchange and influences the lowering of surplus weight. Air cryotherapy includes local methods from -30 to -60 degrees Celsius as well as general from -60 to -150 degrees Celsius. Indications for applying cryotherapy combined with traditional therapy are: inflammatory processes in the organism, degenerative nerve diseases, vertebrae diseases- inflammations and degenerative changes, rheumatic diseases of the soft tissues, collagenoses, myasthenia, myotonia, paralysis, trauma and posttraumatic complications, radioculopathy, etc.
If the cryotherapy is applied directly on the skin and it is fixated on the level of tissues, the application of the given method in dermatology and cosmetology is justified. A short term application or massage with cold, dry air prepares the skin for other medical methods since it activates the capillary microcirculation and the metabolic processes, thus strengthening the membranes. Therefore, masks, body wrappings, injections and physiotherapeutic methods done after cryotherapy are a lot more beneficial and with a more intensive effect. What’s more, this method is completely painless and pleasant since it lowers down the nerve conduction and releases endorphin. Cryotherapy- when combined with cryo massage intensifies the therapeutic effect of other procedures and prevents the appearance of unwanted effects: inflammations, swellings or painful sensations. Moreover, this therapy is used in plastic surgery, laser hair removal, pilings, facial dermoabrasion, etc. The local cryotherapy lasts around 10 to 15 sessions in cases of inflammations and swellings and skin seborrhea. Application and massage with dry air has numerous advantages such as: quick and even dosage of coldness which influences the pathogenic mechanisms and has a healing effect, does not need any equipment, the effect comes immediately after the treatment and lasts around three hours, pleasant and comfortable treatments, no danger from injured skin or traumatized, no side effects, etc. What’s more, this therapy can sometimes ease and even replace medical intervention and it goes well with other methods, although it can be used on its own. Skin problems, such as psoriasis and dermatitis can be solved with the help of cryotherapy since the properly chosen procedures increase the skin elasticity and improve its strength, and intensify the blood circulation which all together contributes to a healthier organism.
The activated process of substances exchange contributes to decrease of weight and prevents cellulite, so the skin regenerates, both with local or general cryotherapy. In some cases, for 20 to 30 treatments a patient can even lose up to 10 kilograms. Due to the high number of long lasting therapeutic effects-up to six months, non-existing side effects and contraindications, cryotherapy is widely applicable in different areas of medicine and cosmetology.