Based on the clinical experiences and results of more than 50 years, this book discusses the theory and best practices of using pillows. It focuses on pillow requirements that address the issue with sleeping posture as well as the history and analysis of problems with the usage of pillows that are now on the market. The book also emphasizes sleep disorders, such as sleep apnea syndrome, as issues that can be resolved by pillows in addition to orthopedic spinal illnesses. Additionally, it describes the significance of utilizing mattresses, comforters, nightwears and other physical elements like lighting and temperature to create a conducive sleeping environment. The topic of keeping proper sleeping posture is also addressed. Since 1972, the author and her father have examined more than 120,000 patients and created a pillow adjustment technique. The authors have developed a method to identify the specific pillow height change that improves the patient's condition based onthese data sets. The patient's condition has significantly improved as a result of the findings, and the book details the most recent development in the study. Professionals can incorporate the findings into their medical procedures to help individuals with their symptoms. Medical professionals who can use the technique and impart the knowledge to their patients, such as doctors, nurses, and engineers, are the intended audience. The English manuscript was created using machine translation (by the service DeepL.com), followed by the author revising, editing, and verifying the translated content.