Mars in Eighth House

If Mars is in the 8th house, the native will suffer from Muscular diseases, he will not be long lived. Father will die early in the native's life and he (native) will suffer from urinary diseases. He will have few children and suffer from rheumatism, shooting pains etc, but will have a happy married life. 

If Mars is in conjunction with a benefic, the native will enjoy good health and will be long-lived.

If Mars is in the house of a malefic or is associated with a malefic, the native will suffer from rheumatism, consumption or from urinary troubles. The span of life will be medium. If the lord of the eighth is powerful, the native will have not have full longevity.

You have powerful desires, with determination and sexual charisma to burn. A skilled researcher, you may be attracted to healing arts and occult subjects. Financial wheeling and dealing may also fascinate you, though money and inheritances can be a source of conflict. Because this position stimulates a yearning for intense experience, you fearlessly take steps that more sensible souls avoid. This placement can bring a degree of wildness, making you irresistible to others — and an occasional danger to yourself.

This position also indicates death in fire and accidents.

Other Views-

Brihat Jatak- The native will have a limited number of issues and will have defective eyesight.

Phaldeepika- The native will have an afflicted body, he will be poor and short-lived and people will speak ill of him.

Saravali- The native will be sickly, short lived and ugly. He will indulge in undesirable activities and will be sorrowful.

Chamatkar Chintamani- If Mars is in the 8th, even other good planets in the horoscope cannot remove the adversities of the native. Even his friends will turn into enemies. He will face obstacles in whatever efforts he makes for his betterment.