Allah’s Messenger (pbuh) said, “Allah has not sent down a disease except that He has also sent down its cure.”
He also said, “Every illness has a cure, and when the (proper) cure is applied to the disease, it is cured with the permission of Allah, the Exalted and Glorious.”
The guidance of the Prophet (pbuh) fired the imagination of Muslim scientists. So medicine occupied the attention of many Muslim scientists over the centuries. This is still alive today in Islamic medicine in some countries.
In the field of medicine, early Muslims concentrated on the use of drugs and herbs rather than surgery. They also knew about the importance of dieting, the climate and mental strain in having an effect on the health of patients. Muslims set up public hospitals with trained, permanent staff, where doctors and scientists could study and do research.
Ibn sina (died 1037 CE) wrote a medical encyclopedia and described how epidemics spread. He was called the prince of physicians in the West. His book The Canon is the most famous book in the history of medicine. Ar-Raazee (d. 925 CE) was the first scientist who told the difference between smallpox and measles. Muslim doctors became great experts in treating eye diseases. Muslim scientists made important advances in optics and the treatment of eye illnesses.
Ibn An-Nafees discovered the minor long circulation of the blood before Michael Servetus who had been credited with it for a time!