Grahan Dosha: Sun or Moon with Rahu/Ketu — an eclipse-like affliction to vitality or mind.
Most "dosha" scares online come from a single rule applied without cancellation checks. The engine here evaluates the classical exceptions too — sign placement, aspects, strength and matching cancellations — so you see whether the dosha is genuinely active or already neutralised.
Check your chart free, and if the dosha is present the report lists the traditional remedies along with the exact period when its effect peaks.