First house in vedic astrology is also called lagna or ascendent. It is used to know about physical appearance, skin color, body constitution, personality and intelligence of the person. In simpler terms the first house in a horoscope is the mirror to the individual whose horoscope is shown. The important thing to know is only a summary is possible through first house. 

     First house is part of Vishnu Sthanas as well as trine called Laxmi Sthanas. Sun in first house is good for health, eyes and confidence. But on the downside the native can have ego issues especially if there are other malefics associated. Moon in first house is good as long as there are no other planets associated with it. Moon gives fair skin, calm attitude and kind nature. But association with other planets may disrupt Moon's natural traits. Mars in first house gives a dusky skin, thin body and over-active personality. Native is a workaholic but prone to anger. Mercury in first house creates a clever, chatty and confident individual but on the downside there can be skin problems and indigestion.

     Jupiter in first house gives smartness, kindness and positive attitude. Jupiter in strength in first house is capable of wiping off all the evil influences in the horoscope. On the downside Jupiter promotes obesity and laziness. Venus in first house gives fair skin, beautiful face and attractive personality. Native is able to charm anyone especially if native is a female. On the downside native is love obsessed. Saturn in first house produces a tall and dark individual. Native is slow and thoughtful in actions. On the downside Saturn increases negativity and chances of mental disease rise in first house. Rahu in first house creates an alluring persona. Native maybe able to attract others with their hypnotic speech and charms. On the downside there can be mental disease and tendency to try illegal activities. Ketu in first house produces dark skin. Ketu in first house normally increases anti-social behavior. Native prefers to be alone and prone to frustrations. 

     First house could very well make or break a person. A right attitude is needed to succeed in life. First house provides looks, health and character to a native which can lead to success or failures in life.