Cold therapy works by reducing blood flow to a particular area, which will reduce inflammation and swelling that causes pain, especially in joints. It can relieve pain by temporarily reduce nerve activity. Bruises, insect bites, and repetitive strain injuries such as tendonitis respond well to cold therapy. Cold therapy helps in the reduction of inflammation, oedema, and bleeding in injuries. Cold therapy will be helpful in reducing toothache, headache, and fever. Cold therapy can help people with muscle spasms, whiplash, and various forms of arthritis as well.
Hot fomentation increases blood flow, delivers needed oxygen and nutrients, and removes cell wastes. The warmth decreases muscle spasm, relaxes the tense muscle, relieves pain, and can increase range of motion. As with cold packs, heat packs will also help in easing pain from both acute and chronic injuries, such as sprains, strains, muscle spasms, whiplash, and arthritis.
Alternating heat and cold may help reduce exercise-induced muscle pain.