i have to disagree with the two above, hexes and curses are two different things. A hex is an incantation which can affect the user for your benefit or just for their detrement. so a hex could be a spell for them to throw away their lives and fortune to be with you, hopelessly in love, or it could be a bad luck hex in which nothing goes their way and they always get the unluck situations, etc.
A curse is an encompassment of ill intentions which can cause harm to another person or some really bad stuff, which can include being plagued by spirits, attacked by poltergheists or demons, health problems, spasms in the body,etc.
In a nutshell a hex is sortof a childish version of harm on someone, a curse is a full on attack on someone with the illest of intentions.