According to one prevalent definition of this dosha, it is said that if Rahu or Ketu are placed in house of ascendant or lagna, with Moon or with Venus, a naga dosha or sarpa dosha is formed in the horoscope which can trouble the native with various kinds of problems depending upon its placement. A naga dosha or sarpa dosha formed with the presence of Rahu or Ketu in lagna is said to bring bad results regarding the health and professional life of the native and this kind of naga dosha or sarpa dosha is also said to cause problems in married life of the native. A naga dosha or sarpa dosha formed by placement of Rahu or Ketu with Moon is said to trouble the native with problems in his professional life, delays, mental problems and some other kinds of problems whereas a naga dosha or sarpa dosha formed due to placement of Rahu or Ketu with Venus is said to cause serious problems in married life of the native and the native under the strong influence of this dosh is not able to enjoy his married life at all and he may have to undergo one or more than one divorces due to the malefic effects of this type of naga dosha or sarpa dosha.
Another definition for naga dosha or sarpa dosha states that if Rahu or Ketu are present in lagna, 2nd, 5th, 7th, or 8th of a horoscope, a naga dosha or sarpa dosha is formed in the horoscope which can trouble the native under its malefic influence with different kind of problems depending upon the placement of Rahu and Ketu in the horoscope. Similarly there are a few more definitions for naga dosha or sarpa dosha and there is a conflict of opinions even regarding the fact whether naga dosha or sarpa dosha are one and the same or they are different doshas. Some astrologers believing in these defects state that naga dosha and sarpa dosha are same defects whereas some other astrologers state that naga dosha is different from sarpa dosha and it is formed under a different set of conditions in a horoscope. But most of the malefic effects associated with naga dosha are similar to the malefic effects associated with sarpa dosha and both of these doshas are said to be formed due to some crimes committed towards snakes or sarpas in the previous life of the native having this dosh in his horoscope. Hence we will treat them as one dosh looking at the malefic results given by them and looking at the reason behind the formation of these doshas.
Let’s now try to analyze naga dosha or sarpa dosha in a scientific way and let’s try to find out whether this dosh is actually formed according to its prevalent definitions or not. Combining both the definitions of naga dosha or sarpa dosha, it can be said that this dosha is formed at least in every second horoscope on average as there are so many houses and planets whose association with either one of Rahu and Ketu is said to form this dosh in a horoscope. For example, the placement of Rahu or Ketu in 1st, 2nd, 5th, 7th, 8th or 11th house or placement of Rahu or Ketu with any one of Moon or Venus is said to form naaga dosha or sarpa dosha in a horoscope. It should be noted here that the placement of Rahu or Ketu in 11th house of a horoscope will mean the placement of the other in 5th house of the horoscope which forms this dosh in the horoscope according to its definition. Hence every second person in this world should be suffering from this dosh on average and going even further, every second person in this world has killed or harmed snakes in his past life because this dosha is said to be formed due to the fact that the native afflicted by this dosh has killed or harmed snakes in his previous life and those snakes have cursed the native due to which a naga dosha or sarpa dosha has been formed in his horoscope. The present population of the world is around 7 billion people which means that about 3.5 billion of these people have killed or harmed snakes in their previous life which further means that about 3 billion snakes have been killed by the present population of the world.
This figure seems too big to digest and the fact that every second person is suffering from such a serious dosha also does not seem practical and reasonable because there is virtually no benefic yoga or malefic dosha in astrology which can be formed in every second horoscope. Yogas and doshas are comparatively rare phenomenon and they are not found present in every horoscope or every second horoscope. Hence it can be safely assumed that naga dosha or sarpa dosha is not formed according to its prevalent definitions and there should be more conditions which need to be met in order for the formation of this dosha in a horoscope. Like in case of many other doshas, the planets forming this dosha in a horoscope which means Rahu and Ketu should be working as malefic planets in a horoscope in order to form a naga dosha or sarpa dosha in the horoscope and both Rahu and Ketu should actively form this dosha in a horoscope as the presence of malefic Rahu and Ketu in some specific houses of the horoscope alone is not sufficient to form naga dosha or sarpa dosha in the horoscope. Once formed, the strength of this dosha, the fields of native’s life which are going to be hit by this dosha and the timing of impact of this dosha should also be calculated before making final predictions about this dosha. The malefic effects of naga dosha or sarpa dosha can be rectified or reduced with the application of astrological remedies like Mantras, Yantras, Pujas, gemstones and some other remedies.