Mercury in 8th house in Astrology represents family or married life, dealing with the in-laws. It signifies joint assets with the family or spouse and how well joint assets will be. It is the house of a cult and secrecy. It is a house of sudden events, secrecy and history.
Mercury in the 8th house in Astrology is not a good position for Mercury to be in as it forces it to be isolated, be a quiet personality, and give lots of skin problems and pain in the back and hands.
Eighth House is known for knowledge of the underground, government taxes, secret government policies. It is a house of sudden events, sudden surgery, a sudden accident or sudden death. Sometimes sudden things include good things like suddenly winning a lottery, suddenly getting a house or a job.
The native of Mercury in the eighth house applies intelligence and the logical mind into digging for things. The native could be a palaeontologist, an archaeologist or in any relevant field as they dig deep to learn or observe or analyse something because analysing data comes with intelligence.
The eighth house is also significant in terms of the throat, family history and family lineage. The native, by digging deep in their family history, learns about his family and makes it resourceful. The Mercury in the eighth house is significant in speech and enhancement of speaking abilities. The native can be very communicative with the in-laws and family, but miscommunication with family is expected if planets are displaced.
The native's communicative ability goes into the deep philosophical things of life. The curiosity of knowing and learning new things in the eighth house can lead natives to dig for intellectual things. It can be troublesome when it is rerouted towards dealing with family issues because family issues are not as intellectual.
The 8th House rules the death and rebirth of a person or how one rises after a great fall in their life. This house also shows money through in-laws and friends as loans from them. Financial loans for home or business is also shown from this house.
Deep-rooted issues of one's life and one’s interests or lack of interests in the mystical world such as astrology, magic, tantric practices, and ghosts are shown from this house. 8th house also represents the life span of a person. This is simply the house of the occult.
Government taxes, spies, and business-related to secret government dealings are seen from the 8th house. The 8th house is a death-inflicting house (Marka House), as the 8th house deals with things buried deep beneath the earth.
Physically, the 8th House corresponds to the lowest part of the trunk, the genitals, anus, and the eliminatory system. Scorpio corresponds to the 8th house and adds the signification of sudden calamities.
Mercury in 8th House makes a person intelligent, because, in order for anyone to have good communication, one needs to be intelligent.
Mercury also represents a native’s business and management skills due to his calculative and logical nature and love for the marketplace.Mercury in Astrology represents speech.
It also governs the logical and intellectual side of the mind, the thinking process that precedes speech, the ability to communicate and anything related to language, whether it’s using symbols, logic, information processing, or connecting with people or things.
Note: The degree of auspiciousness and inauspiciousness will depend upon a complete analysis of the horoscope (birth-chart).