The 'Essentials of Medical Astrology' is the standard book on Vedic astrology which lays down detailed principles relevant to the analysis of a horoscopic chart, with disease and its various aspects as the main focus of attention. Some of the prominent features of this work are: > Standardisation of approach to analysis of a chart related to disease. > Use of four vargas, or divisional charts, and two dashas to ensure an accurate assessement of the chart. > Discussion of principles of sound and unsound health. > Indications for congenital ailments. > An elaborate approach to ensure accurate timing of onset of disease and its outcome. > Hints about the possible site of disease as well as the nature of disease using the significations of houses and planets, and the Drekkanas. > A detailed account of the principles of Balarishta and Arishta-Bhanga. > The use of such subtle principles of Vedic astrology as the twenty-second Drekkana, the sixty-fourth Navamsha, the Sarpa Drekkana, and Gulika or Mandi, to decide on the onset and outcome of illness. > Classical combinations indicating some of the common ailments, and the scientific approach to application of these principles to actual horoscopic charts.