The Hadiths of the Prophet contain many instructions concerning health including dietary habits; these sayings became the foundation of what came to be known later as "Prophetic medicine" (al-tibb al-nabawi). Because of the great attention paid in Islam to the need to take care of the body and to hygiene, early in Islamic history Muslims began to cultivate the field of medicine turning once again to all the knowledge that was available to them from Greek, Persians and Indian sources. At first the great physicians among Muslims were mostly Christian but by the 9th century Islamic medicine, properly speaking, was born with the appearance of the major compendium, The Paradise of Wisdom (Firdaws al-hikmah) by 'Ali ibn Rabban al-Tabari, who synthesized the Hippocratic and Galemic traditions of medicine with those of India and Persia. His student, Muhammad ibn Zakariyya' al-Razi (the Latin Rhazes), was one of the greatest of physicians who emphasized clinical medicine and observation. He was a master of prognosis and psychosomatic medicine and also of anatomy. He was the first to identify and treat smallpox, to use alcohol as an antiseptic and make medical use of mercury as a purgative. His Kitab al-hawi (Continens) is the longest work ever written in Islamic medicine and he was recognized as a medical authority in the West up to the 18th century.
The greatest of all Muslim physicians, however, was Ibn Sina who was called "the prince of physicians" in the West. He synthesized Islamic medicine in his major masterpiece, al-Qanun fi'ltibb (The Canon of Medicine), which is the most famous of all medical books in history. It was the final authority in medical books in history. It was the final authority in medical matters in Europe for nearly six centuries and is still taught wherever Islamic medicine has survived to this day in such land as Pakistan and India. Ibn Sina discovered many drugs and identified and treated several ailments such as meningitis but his greatest contribution was in the philosophy of medicine. He created a system of medicine within which medical practice could be carried out and in which physical and psychological factors, drugs and diet are combined.
After Ibn Sina, Islamic medicine divided into several branches. In the Arab world Egypt remained a major center for the study of medicine, especially ophthalmology which reached its peak at the court of al-Hakim. Cairo possessed excellent hospitals which also drew physicians from other lands including Ibn Butlan, author of the famous Calendar of Health, and Ibn Nafis who discovered the lesser or pulmonary circulation of the blood long before Michael Servetus, who is usually credited with the discovery.
As for the western lands of Islam including Spain, this area was likewise witness to the appearance of outstanding physicians such as Sa'd al-Katib of Cordoba who composed a treatise on gynecology, and the greatest Muslim figure in surgery, the 12th century Abu'l-Qasim al-Zahrawi (the Latin Albucasis) whose medical masterpiece Kitab al-tasrif was well known in the West as Concessio. One must also mention the Ibn Zuhr family which produced several outstanding physicians and Abu Marwan 'Abd al-Malik who was the Maghrib's most outstanding clinical physician. The well known Spanish philosophers, Ibn Tufayl and Ibn Rushd, were also outstanding physicians.
Islamic medicine continued in Persia and the other eastern lands of the Islamic world under the influence of Ibn Sina with the appearance of major Persian medical compendia such as the Treasury of Sharaf al-Din al-Jurjani and the commentaries upon the Canon by Fakhr al-Din al-Razi and Qutb al-Din al-Shirazi. Even after the Mongol invasion, medical studies continued as can be seen in the work of Rashid al-Din Fadlallah, and for the first time there appeared translations of Chinese medicine and interest in acupuncture among Muslims. The Islamic medical tradition was revived in Safavid period when several diseases such as the first time and much attention was paid to pharmacology. Many Persian doctors such as 'Ayn al-Mulk of Shiraz also traveled to India at this time to usher in golden age of Islamic medicine in the subcontinent and to plant the seed of the Islamic medical tradition which continues to flourish to this day in the soil of that land.
The Ottoman world was also an arena of great medical activity derived from the heritage of Ibn Sina. The Ottoman Turks were especially known for the creation of major hospitals and medical centers. These included not only units for the care of the physically ill, but also wards for patients with psychological ailments. The Ottomans were also the first to receive the influence of modern European medicine in both medicine and pharmacology.
In mentioning Islamic hospitals it is necessary to mention that all major Islamic cities had hospitals; some like those of Baghdad were teaching hospitals while some like the Nasiri hospital of Cairo had thousands of beds for patients with almost any type of illness. Hygiene in these hospitals was greatly emphasized and al-Razi had even written a treatise on hygiene in hospitals. Some hospitals also specialized in particular diseases including psychological ones. Cairo even had a hospital which specialized in patients having insomnia.
Islamic medical authorities were also always concerned with the significance of pharmacology and many important works such as the Canon have whole books devoted to the subject. The Muslims became heir not only to the pharmacological knowledge of the Greeks as contained in the works of Dioscorides, but also the vast herbal pharmacopias of the Persians and Indians. They also studied the medical effects of many drugs, especially herbs, themselves. The greatest contributions in this field came from Maghribi scientists such as Ibn JulJul, Ibn al-Salt and the most original of Muslim pharmacologists, the 12th century scientist, al-Ghafiqi, whose Book of Simple Drugs provides the best descriptions of the medical properties of plants known to Muslims. Islamic medicine combined the use of drugs for medical purposes with dietary considerations and a whole lifestyle derived from the teachings of Islam to create a synthesis which has not died out to this day despite the introduction of modern medicine into most of the Islamic world.