cryotherapy
Meaning of cryotherapy: Cold used to soothe and cold used to kill tissue share one name, separated only by how far the temperature is taken.
Definition of cryotherapy
Cryotherapy is the use of cold as a treatment. The word stretches from an ice pack held against a sprain to a probe that freezes a tumor solid, and the two ends of that range work by completely different mechanisms. Mild cooling slows blood flow and nerve signals, while extreme cold destroys the tissue it is applied to.
How does cold destroy tissue?
Freezing kills in several ways at once. Ice crystals form outside the cells first and draw water out of them, and as the temperature drops further crystals form inside the cells and tear the membranes apart. Small blood vessels within the frozen zone clot and shut down, so whatever survives the freeze is starved afterward. Thawing does further damage as the crystals grow, which is why treatment is usually applied as repeated freeze and thaw cycles rather than one long freeze. Liquid nitrogen is the usual agent at the skin surface, while argon gas expanding through a needle probe is used for deeper targets. Only tissue that actually reaches a killing temperature is destroyed, so the size of the frozen zone decides the result.
What is it used for?
| Use | How the cold is applied |
|---|---|
| Warts, sun damaged patches and other precancerous spots | Liquid nitrogen sprayed or dabbed onto the skin |
| Some early skin cancers | Liquid nitrogen, where the lesion is small and well defined |
| Tumors in the kidney, liver, lung, prostate or bone | A needle probe guided by imaging, an approach called cryoablation |
| Abnormal heart rhythms | A catheter probe freezing the small area generating the rhythm |
| Sprains, strains and swelling after injury | An ice pack or cold wrap on intact skin |
Where does whole body cryotherapy fit?
Standing briefly in a chamber cooled by nitrogen vapor or refrigerated air is marketed for muscle recovery, pain, mood and general wellness. It sits apart from the medical uses listed above, since the skin is chilled for a short time and no tissue is meant to be destroyed. Evidence for the claimed benefits is thin and the studies are small, and the practice carries recognized hazards including cold burns, frostbite and, where nitrogen vapor displaces air in a poorly ventilated chamber, suffocation. This marketed use of the same word is the main reason cryotherapy is often assumed to mean one thing when it covers a range of quite different procedures. A skin cancer frozen off by a dermatologist and an athlete standing in a cold chamber are linked by temperature alone.
Also known as
Used in a sentence
Cryotherapy with liquid nitrogen was used to remove the wart during the office visit.
Good to know
Cryotherapy applied to destroy a specific lesion, as in freezing a wart or a small tumor, is a distinct use from cryotherapy applied broadly to reduce swelling or pain after an injury.
Word origin
Where “cryotherapy” comes from
Formed from Greek kryos, meaning cold, and therapeia, meaning treatment.