In Vedic astrology, Rahu Mahadasha activates certain energies and influences in a person’s life. Rahu is considered to be a shadow planet, and its Mahadasha period lasts for 18 years.

During this time, Rahu’s energy is said to become prominent and affect different areas of a person’s life. Some possible effects of Rahu Mahadasha include:

1. Ambition and desire for material success may increase.
2. The person may become more assertive and confident.
3. Relationships and partnerships may undergo changes and challenges.
4. Health issues may arise, especially related to the nervous system or psychological well-being.
5. There may be opportunities for travel, exploration, and learning.
6. Spiritual pursuits and practices may become more important or prominent.

Some of the effects which are negative in nature are:

1. Rahu is very greedy, materialistic pleasure loving, love to achieve the result or success by hook or crook. Doesn’t believe much in hard work in other word doesn’t believe in donkey work but in monkey work and so rahu would always like to short cut and risk.
2. Rahu has the power of reading people like book, have very good intuition power and so can guess things or any action in advance.
3. Rahu is an illusionist / magician and create an illusion ( its not real ) in such a way that the people are compelled to believe it.
4. Rahu doesn’t speak complete truth his story is always manipulated. He presents the story in such a way that the other person feels that he heard the complete story.
5. Rahu is a gambler and often make good money in gambling as he believes much in effort less earning.
6. Rahu can’t be trusted as he has tendency to cheat you. Rahu is very curious to know about others. He feels that he should have everyone’s information with him.
7. Rahu is smoky in nature and has the ability to adapt and change himself ( change face ) from time to time and so a spying nature is inborn talent and can be at a time disguise himself in such a way that his nearest person can’t recognize him at one shot.
8. Rahu will always push to higher goal to make more and more money and this is the reason that in rich people’s horoscope rahu is in good position to give them amazing wealth.
9. Rahu doesn’t love to obey rules and regulation and therefore do actions of his will. This is one of the reasons why rahu prefer to do intercaste marriage of his choice.
10. The hunger and desire of materialistic pleasure is so much in rahu that one a person fall in the clutch of a negative rahu will get drowned in doldrums.

It is important to note that the effects of Rahu Mahadasha can vary depending on the individual’s birth chart and other factors like placement of the planets in an individual horoscope is also plays an important role in giving their impacts and thus gives their impacts on Rahu’s results.