Acupuncture is a form of alternative medicine in which thin needles are inserted into the body. It is a key component of traditional Chinese medicine (TCM). TCM theory and practice are not based upon scientific knowledge, and acupuncture is a pseudoscience. There is a diverse range of acupuncture theories based on different philosophies, and techniques vary depending on the country. The method used in TCM is likely the most widespread in the United States. It is most often used for pain relief, though it is also used for a wide range of other conditions. Acupuncture is generally used only in combination with other forms of treatment. Acupuncture is the insertion of thin needles into the skin. According to the Mayo Foundation for Medical Education and Research (Mayo Clinic), a typical session entails lying still while approximately five to twenty needles are inserted; for the majority of cases, the needles will be left in place for ten to twenty minutes. It can be associated with the application of heat, pressure, or laser light. Classically, acupuncture is individualized and based on philosophy and intuition, and not on scientific research. There is also a non-invasive therapy developed in early 20th century Japan using an elaborate set of "needles" for the treatment of children (shōnishin or shōnihari)