People sometimes loses job suddenly, gets diseases which wont get cured, fight happens in their family .All these may be the result of black magic upon you.
The word Jaadu (magic) originated in Vedic era from the term YAATU,which has been mentioned in Atharva veda many times.Vedic rishi prays to agni,Indra,Varuna,vanaspati to protect him from rakshasas and such cruel powers.
Atharva veda uses the word Yaatu for Rakashas (demons).Other than for demons, yaatu word has been used for traveller (yaatri),air,bhoot pret,pishach. Sundarakhand uses this word,but by that era ,the word got transformed as jaatu.
Raakshasa are adept in performing jaadu.As time went on,the word yaatu in atharva veda became known as jaadu in Farsi language.Other than this, jaadu-tona,cheating,cunningness,and Indrajaal uses this word jaadu.(magic).
Jaadu does not mean magic show here, it means extraordinary power ,specifically that of evil powers that destroys the good things in our life.Great poet Tulsidas says just by remembering the name of lord hanuman,such evil powers gets destroyed.Wearing kavach of hanuman prevents us from such evil powers.
Atharva veda criticises such cruel persons in harsh language ,that let curse of such evil persons upon me, get returned to them .Let us get good hearted people as our friends.
Such enemies tries to destroy your mental power.Tantra baadha nivaaran deeksha is good to prevent black magic upon you.