Rahu in the 3rd house (Sahaja, the house of courage) brings the significations of Rahu, namely obsession & ambition, foreign lands & the unconventional, illusion (maya), into the area of courage, self-effort, siblings and communication. The 3rd house governs courage & effort, younger siblings, communication & skills, short journeys.
Results of Rahu in the 3rd House
Rahu is a malefic planet, so here it tends to bring confusion, anxiety, deceit, addictions and unexpected upheaval focused on courage, self-effort, siblings and communication.The exact result depends on which sign Rahu occupies here and the aspects it receives.
When It Activates
These results typically surface during the Vimshottari mahadasha or antardasha of Rahu, and when transiting planets trigger the 3rd house. A well-placed Rahu here supports bravery, initiative, talent and good bonds with siblings; when afflicted it can indicate timidity, lack of drive and strained sibling relationships.