Some charts may not only not be good for relationship, they may threaten the life, health success or well-being of the partner. This was the basis of the Kuja Dosha or the difficult placement of Mars. Such factors include all the issues of Kuja Dosha. They include malefics in the eighth house, like Mars, Rahu, Ketu or Saturn or the lord of the seventh in the eighth house.
For example, the chart of a client who had contracted AIDS had Gemini Ascendant with Jupiter, the lord of the seventh, at its maximum degree of debility in the eighth house in Capricorn.
This person lost many partners to the disease.If a woman has a very strong Mars, it may prove difficult for the partner, unless his Mars or Sun is very strong. If a woman has a strong Sun, it does not threaten the life of the partner but may repel potential partners. Similarly, a man with a very weak Mars or Jupiter may not be helpful to a woman. A weak Mars will not give him enough courage in life. A weak Jupiter will give him misfortune. We must always remember that whoever we enter into partnership with, we tend to take on the karma in their birthchart.