die Hauptursache
Translation
main cause, primary cause, root cause
Examples
Stress ist die Hauptursache für viele Krankheiten.
Stress is the main cause of many illnesses.
Die Polizei ermittelt die Hauptursache des Unfalls.
The police are investigating the main cause of the accident.
Grammar Patterns
the main cause ((for sth.)) Stress is the main cause for the problem.
the main cause ((of sth.)) That is the main cause of the conflict.
Similar Words
der Hauptgrund (main reason), die Wurzel des Übels (the root of the evil)
Etymology
Composed of 'Haupt-' (main, chief) and 'Ursache' (cause, reason). It literally means 'main cause'.
Memory Tips
Think of it as the 'head' (Haupt) cause, the one from which all other problems stem.