The science of Astrology has fascinated mankind since the times immemorial. The origin of Indian Astrology or Jyotish is said to be when history fades in to myths. The word Jyotish is derived from two words, 'Jyoti' meaning light and 'Ishwar' meaning God. If literarily translated, it means the light of God. Since ages, this light of knowledge has guided the humanity in various chores of life. Its importance in the Vedic period can be acknowledged by the fact that the principles of Jyotish were strewed in all the four Vedas.
In the first chapter of Brihat Parashar Hora, one of the oldest classics of Jyotish, Lord Brahma says that as Sun which is the leader among planets gives light to the world; similarly Jyotish illuminates the treasure of Vedas. This science is said to be eternal and its origin was on the similar lines of Ayurveda. Lord Brahma first gave the knowledge of Jyotish to Sage Narada who passed it to Maharishi Saunaka. Rishi Parashara was the son of Rishi Saunak and the great treatise Brihat Parashar Hora was written in the form of a dialogue between him and his disciple Maitreya. The philosophy of good health which stands at the very root of Dharma, Artha, Kama and Moksha is found in the texts of both Jyotish and Ayurveda. These two sciences were very closely related and it can be judged by the fact that in the olden days every Vaidya had good knowledge of Jyotish as well. Many of the classics of these sister sciences have amalgamated each others principles in various chapters.

The theory of 'Yat Brhmande Tat Pinde, Yat Pinde Tat Brahmande' directly answers the question of how planets rule the body. It means that whatever is in the Universe is there in the body and vice versa. The theory is very absorbing; as it eulogizes that the knowledge contained in the Vedas is in total harmony with nature. The Brihat Parashar Hora has explained three skandha or the pillars of Jyotish as Ganita, Hora and Samhita. The Phalita or the art of Prediction comes under the Hora skandha which is also considered the finest among the three. It explains of nine planets consisting of Sun, Moon, Mercury, Venous, Mars, Jupiter, Saturn, Rahu and Ketu. Of these Rahu and Ketu are the two planets which do not have any physical existence. They are referred as shadow planets which are formed from the North and South node of intersection of Earth's and Moon's orbit.

The Hora also explains of twelve signs and twenty seven Nakshtras which cover the 360° of Arc distance around the Earth. Each sign occupies a distance of 30°, so every sign consists of three Nakshtras each in divided Padas. Within this Skandha, another striking concept of Kaal Purusha is illustrated. Kaal purusha is an imaginary personification of time. Various body parts of the Kaal Purusha are in direct confluence with the twelve signs and the nine planets of the cosmos.

In a common North Indian Style Chart there are twelve houses which also signify different parts of the body. The sequence is similar to that of signs. The first house referred as the Lagna is the most important, as it signifies the head, prakarti and the general built of the body. The respective parts of the body get affected if the corresponding planet in the birth chart is afflicted. There are various permutations and combinations of Planets, Signs and Nakshtras which can affect the quality of health of a native in different ways. An astrologer who has a good in depth knowledge and knows the art of prediction can easily infer the health condition of the native. One of the famous classical compendiums on Medical astrology, Veer Singhavaloka which was penned down by King Veer Singh several years ago, gives the description of each disease according to the planetary combinations. The book also enumerates various measures to pacify the ill effects of a planet along with the use of various herbal formulations. The measure includes Homa, Mantra Uccharan, Daan, Aushadhi etc.

Another remedial measure in Jyotish is the colour therapy. Each planet is coupled with a colour, which helps every astrologer in treating a disease. If an afflicted planet causes a disease in an organ, it can be stimulated by a specific wavelength of colour. Each planet also has a Ratna or Uparatna corresponding to it. In the Stone therapy the native is said to wear the relative stone on its body to veil off the bad effects of a planet.

This concept of Medical astrology is fast catching up nowadays, with many doctors of Ayurveda and other allied sciences are practicing it. Jyotish specifies that medicine taken on the Eighth day of the waxing and waning of moon is comparatively more effective. If the modern investigating techniques fall short in conclusion then Jyotish becomes a very powerful tool in diagnosing the disease of the native. The time is ripe now when the principles of Jyotish should also be included in the curriculum of Ayurveda for the benefit of the mankind.