In order to provide joyful and perfection to the householder's life, Indian mystics gave many rules regarding the physical, mental and progeny welfare before the marriage of boy and girl. In which Mangal Dosh has been conside as the most important. Mangal Dosh has been conside most important just because Mars's role in a married life. Generally, Mars is called an energetic planet, but being a malefic planet, this planet occupies an important place in the category of the annihilating planet.
This is the planet that plays an important role in communicating internal energy as well as making coordination among both men and women.
The most specific fact that is related to married life is that Mars has complete authority over the semen of the man as well as the woman's body. Mars represents two zodiac signs in the solar system known as Aries and Scorpio. In the janmang of male Aries is the lord of head while Scorpio is the lord of private parts. Aries is igneous by nature where as Scorpio sign is aquatic in nature.
Mars has equal rights over masculinity and femininity due to its aquatic and igneous quality. Hence when it sits in the first, fourth, seventh, eighth, and twelveth house then it makes a man Mangala and a woman Mangali. When Mars becomes unbalanced in the horoscope of both, then it creates problems in the householder life. As Mars occupies in five houses it controls conscience, nature, happiness, peace, nature, pleasure, peace, deceit, woman, death, sexual pleasure etc. Due to which the imbalance of Mars is in a position to give a negative effect.
The most noticeable fact here is that occuping in the ascendant, fourth, seventh, eighth and twelfth house of a boy or girl in the horoscope makes them a mere mangala or mangali. Being Mangala and having Mangala Dosha are both different subjects. Being mangala is a specialitty of house placement but mangala dosh is a Marak position or fatal position. Mangala Dosha is basically a negative state affecting household's pleasures of physical, mental, family child etc.
Therefore, the presence of Mars in the five houses should not be considered as a dosha, but only after making a detailed analysis on the house position, the elemental position, yogic position, non-yogic position, aspect of other planets etc. the dosha should be mentioned.
The fact of Mangala and Mangala Dosha has been clarified by Astroterminal after following each theory of Indian astrology, as well as extensive researches on many horoscopes.