The rising sign
The lagna, or ascendant, is the zodiac sign that was rising on the eastern horizon at your birth. It anchors the whole chart: the lagna becomes the first house, and every other house is counted from it, so changing the lagna changes what every planet in the chart is taken to govern.
Why the birth time matters most here
The ascendant moves through a full sign in roughly two hours, so it is the single most time-sensitive point in a chart. An error of a few minutes rarely changes the rashi, but it can change the lagna entirely and with it the reading of the whole horoscope. If your recorded time is uncertain, treat the lagna with caution.
What it describes
Where the Moon describes the mind, the lagna describes the body, the constitution and the way a person meets the world. Its lord — the planet ruling the rising sign — is one of the most important planets in any chart, and its condition is read before almost anything else.
Common questions
How accurate does my birth time need to be?
The ascendant moves a full sign in about two hours, so a few minutes rarely matters but half an hour can. If your time is recorded only to the nearest hour, treat a lagna near the start or end of a sign as uncertain.
What is the difference between lagna and rashi?
The lagna is the sign rising in the east at your birth and governs the body and constitution. The rashi is the sign holding the Moon and governs the mind.