The history of medical diagnosis began in earnest from the days of Imhotep in ancient Egypt and Hippocrates in ancient Greece but is far from perfect despite the enormous bounty of information made available by medical research including the sequencing of the human genome. The practice of diagnosis continues to be dominated by theories set down in the early 20th century.
Antiquity
Ancient Egypt
An Egyptian medical textbook, the Edwin Smith Papyrus written by Imhotep (fl. 2630-2611 BC), was the first to apply the method of diagnosis to the treatment of disease. Physicians in Ancient Egypt were only able to come up with diagnostics based on symptoms, no tests were being run. Most physicians in this time had the ability to identify problems with the digestive tract, cardiovascular system, spleen, liver, and menstrual cycle; However, the top tier medical treatments, and physicians were only used for royalty and wealthy Egyptians.
The first type of modern medical care has been found in Ancient Egypt (3300BCE to 525BCE). Ancient Egyptians believed that the relationship a person has with the universe determines their health. Hence, they did not make a significant difference between medicine and magic, Ebers Papyrus implemented the basic concept of health and disease, which says that the body has twnty-two mtw (vessels) that connect to the body with essential substances like semen, mucus, tears, air and blood.
Ancient Babylonia
A Babylonian medical textbook, the Diagnostic Handbook written by Esagil-kin-apli (fl. 1069-1046 BC), introduced the use of empiricism, logic and rationality in the diagnosis of an illness or disease. The book made use of logical rules in combining observed symptoms on the body of a patient with its diagnosis and prognosis. He described the symptoms for many varieties of epilepsy and related ailments along with their diagnosis and prognosis which both played significant roles in the practice of Babylonian medicine.
Babylonian physicians had to pay very close attention to the patient and every sign that their body produced that could be relevant to the illness. They were very keen on the temperature of the body. Physicians could only tell temperature based on the feel of it. They had multitudes of classifications for each slightly different increase and decrease in the patient's fever and how they should treat that person. Another way they were able to diagnosis problems was by looking at every possible afflicted area. They made great contributions to diagnosing problems such as pneumonia by observing the throat and phlegm of the affected person.
Ancient China
Predated by Babylonian and Egyptian medicine, traditional Chinese medicine (TCM) was described in an ancient Chinese text, the Yellow Emperor's Inner Canon or Huangdi Neijing which dates to the first or second century BCE. The four diagnostic methods of TCM which are still being practiced today are inspection, listening and smelling, inquiry and palpation.
Ancient Greece
Over two thousand years ago, Hippocrates recorded the association between disease and heredity. In similar fashion, Pythagoras noted the association between metabolism and heredity (allergy to Fava beans). The medical community, however, has only recently acknowledged the importance of genetics and its relevance to mainstream medicine.