Theodor Kocher was a Swiss physician best known as a Nobel Prize winner for his work in Physiology, pathology and surgery. Theodor was interested in the field of medicine since his early years. Following his high school graduation, he enrolled at the University of Bern and completed his studies in 1865. After travelling across Europe, he returned to Bern and took a top position in the faculty of the University of Bern, where he worked almost all his life. He was known for his work on aseptic surgery and thyroid treatments. He revolutionized thyroid treatments with his slow and precise methods. He reduced the loss of blood and his patients had very less mortality rates while going through thyroid surgery. He also established that the thyroid gland should not be removed completely as it could lead to mental and physical issues in patients. The modern thyroid treatments using hormone replacement therapy owed greatly to the research conducted by Theodor. He was awarded the 1909 Nobel Prize in Physiology or Medicine. He also wrote several books and medical journals and remains one of the most influential medical practitioners and surgeons of all time.