Ultrasound is a sound wave whose frequency is too high to be heard by humans. Ultrasound has its uses in medicine. They also help to alleviate a number of ailments. Ultrasound is used, for example, for post-traumatic conditions, degenerative diseases of the spine and joints, "heel spurs", treatment of lymphatic swellings, rheumatic diseases, treatment of contractures, scars and haematomas. High sound has also proved to be extremely effective in cosmetic treatments. Ultrasound in cosmetics is used for certain treatments, such as cavitation peeling, non-invasive facelifts and slimming and firming treatments.