Cryotherapy is the local or general use of low temperatures in medical therapy. Cryotherapy is used to treat a variety of benign and malignant tissue damage, medically called lesions. The term "cryotherapy" comes from the Greek cryo (κρύο) meaning cold, and therapy (θεραπεία) meaning cure.
The most prominent use of the term refers to the surgical treatment, specifically known as cryosurgery or cryoablation. Cryosurgery is the application of extreme cold to destroy abnormal or diseased tissue and is used most commonly to treat skin conditions.
Cryotherapy is widely used to relieve muscle pain, sprains and swelling either via soft tissue damage or postoperative swelling. It can be a range of treatments from the very low technology application of ice packs or immersion in ice baths (generally known as cold therapy) to the use of cold chambers (whole body or partial body cryotherapy) and or face masks or body cuffs with controlled temperature, sometimes called hilotherm.
While cryotherapy is widely used, there appears to be little evidence as to its efficacy that has been replicated or shown in large controlled studies. Also its long term side effects have not been studied.  Commonly, reports regarding cryotherapy suggest further research is needed.
Cryosurgery is the application of extreme cold to destroy abnormal or diseased tissue. The application of ultra-cold liquid causes damage to the treated tissue due to intracellular ice formation. The degree of damage depends upon the minimum temperature achieved and the rate of cooling. Cryosurgery is used to treat a number of diseases and disorders, most especially skin conditions like warts, moles, skin tags and solar keratoses. Liquid nitrogen is usually used to freeze the tissues at the cellular level. The procedure is used often as it is relatively easy and quick, can be done in the doctors surgery, and is deemed quite low risk. If a cancerous lesion is suspected then excision rather than cryosurgery may be deemed more appropriate.
Ice pack therapy
Ice pack therapy is a treatment of cold temperatures to an injured area of the body. Though the therapy is extensively used, and it is agreed that it alleviates symptoms, testing has produced conflicting results about its efficacy.
An ice pack is placed over an injured area and is intended to absorb heat of a closed traumatic or edematous injury by using conduction to transfer thermal energy. The physiologic effects of cold application include immediate vasoconstriction with reflexive vasodilation, decreased local metabolism and enzymatic activity, and decreased oxygen demand. Cold decreases muscle spindle fiber activity and slows nerve conduction velocity, therefore it is often used to decrease spasticity and muscle guarding. It is commonly used to alleviate the pain of minor injuries, as well as decrease muscle soreness. The use of ice packs in treatment decreases the blood flow most rapidly at the beginning of the cooling period, this occurs as a result of vasoconstriction, the initial reflex sympathetic activity.
Ice is not commonly used prior to rehabilitation or performance because of its known adverse effects to performance such as decreased myotatic reflex and force production, as well as a decrease in balance immediately following ice pack therapy for 20 minutes. However, if ice pack therapy is applied for less than 10 minutes, performance can occur without detrimental effects. If the ice pack is removed at this time, athletes are sent back to training or competition directly with no decrease in performance.
Cold spray anesthetics
In addition to their use in cryosurgery, several types of cold aerosol sprays are used for short-term pain relief. Ordinary spray cans containing tetrafluoroethane, dimethyl ether, or similar substances, are used to numb the skin prior to or possibly in place of local anesthetic injections, and prior to other needles, small incisions, sutures, and so on. Other products containing chloroethane are used to ease sports injuries, similar to ice pack therapy.
Whole body cryotherapy
Whole body cryotherapy (WBC) is an alternative to cold water immersion or ice packs. While further studies to determine the efficacy of the treatment are recommended a review of the available data does not show that this treatment has a greater impact than simple ice pack therapy or ice bath.
This treatment involves exposing individuals to extremely cold dry air (below −100 °C) for two to four minutes. To achieve the subzero temperatures required for WBC, two methods are typically used: liquid nitrogen and refrigerated cold air. During these exposures, individuals wear minimal clothing, which usually consists of shorts for males, and shorts and a crop top for females. Gloves, a woollen headband covering the ears, and a nose and mouth mask, in addition to dry shoes and socks, are commonly worn to reduce the risk of cold-related injury. The first WBC chamber was built in Japan in the late 1970s, but WBC was not introduced to Europe until the 1980s, and has only been used in the US and Australia in the past decade.
Whole body cryotherapy was initially intended for use in a clinical setting to treat patients with conditions such as multiple sclerosis and rheumatoid arthritis. WBC is provided in over 50 European hospitals and medical clinics and it has now been used in many spas, and athletic training facilities as well. Elite athletes have reported using the treatment to alleviate delayed onset muscle soreness (DOMS) after exercise and recreational athletes have started to emulate elite athletes in using these treatments after exercise. Reductions in muscle and skin tissue temperature after WBC exposure may stimulate cutaneous receptors and excite the sympathetic adrenergic fibres, causing constriction of local arterioles and venules. There has been a study that suggests that WBC stimulates the autonomic nervous system (ANS), with a predominance of parasympathetic tone activation, after exposure but it does not appear to have been duplicated.
Systematic reviews of whole body cryotherapy have repeatedly called for research studies to implement active surveillance of adverse events, which are suspected of being underreported. If the cold temperatures are produced by evaporating liquid nitrogen, there is the risk of inert gas asphyxiation as well as frostbite.
Partial body cryotherapy
Partial Body Cryotherapy (PBC) devices or 'cryosaunas' are cylindrical chambers, typically having an aperture at the top, with the patient's head remaining outside and not subjected to the cold stimulus. These devices are commonly used throughout United States and are erroneously referred to as offering "Whole Body Cryotherapy". A further key difference between PBC and WBC is the usage of injection of evaporated liquid nitrogen into the PBC chamber with the potential adverse effects as listed below.
A small study of 15 participants published in the September 2000 edition of the Archives of Family Medicine showed that a combination of pressure and cold temperatures, both applied locally via a headband, can successfully mitigate headache-related pain and also decrease the duration of a headache. Eighty-seven percent of participants (p=.004) said that the combination of pressure as well as temperature therapy was "optimally effective"; 13% said that the temperature therapy was "moderately effective".
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- Cryotherapy Helped Leicester City Win The Premier League Championship