Cold treatment reduces blood flow to an injured area. This slows the rate of inflammation and reduces the risk of swelling and tissue damage. It also numbs sore tissues, acting as a local anesthetic, and slows down the pain messages being transmitted to the brain.
Ice can help treat a swollen and inflamed joint or muscle. It is most effective within 48 hours of an injury.
Rest, ice, compression and elevation (RICE) are part of the standard treatment for sports injuries.
Note that ice should not normally be applied directly to the skin.
A cold mask or wrap around the forehead may help reduce the pain of a migraine.
For osteoarthritis, patients are advised to use an ice massage or apply a cold pad 10 minutes on and 10 minutes off.
Ice is best used on recent injuries, especially where heat is being generated.
It may be less helpful for back pain, possibly because the injury is not new, or because the problem tissue, if it is inflamed, lies deep beneath other tissues and far from the cold press.
Back pain is often due to increased muscle tension, which can be aggravated by cold treatments.
For back pain, heat treatment might be a better option.
When cold is applied to the body, the blood vessels contract, vasoconstriction occurs. This means that circulation is reduced, and pain decreases.
Removing the cold causes vasodilation, as the veins expand to overcompensate.
As the blood vessels expand, circulation improves, and the incoming flow of blood brings nutrients to help the injured tissues heal.
Alternating heat and cold can be useful for:
osteoarthritis
exercise-induced injury or DOMS
Contrast water therapy (CWT) uses both heat and cold to treat pain. Studies show that it is more effective at reducing EIMD and preventing DOMS than doing nothing.
Heat should not be used on a new injury, an open wound, or if the person is already overheated. The temperature should be comfortable. It should not burn.
Ice should not be used if a person is already cold. Applying ice to tense or stiff muscles in the back or neck may make the pain worse.
Heat and cold treatment may not be suitable for people with diabetic neuropathy or another condition that reduces sensations of hot or cold, such as Raynaud’s syndrome, or if they are very young or old, or have cognitive or communication difficulties.