Some signs of being cursed may be a random chronic pain. You luck, health, or love life getting worse as the days pass by. It usually depends on who hexed you and what the hex was intended to do. If it was intended to harm your fincances, you may go through a bad time where you lose your job and have trouble finding a new one. Or if it affects your love life, you and your current partner, or whomever you love, will may be start constantly fighting.
Curses can affect you in many ways, some will even attack your health, appearing as a sickness. When you go to the doctor, they may find something wrong, or they may say it's a virus. However, I would still recommend going to the doctor, because this will treat the physical ailments. When you go home you should cleanse off the spiritual ailment/curse.
Here's a wonderful post on how to tell if you're cursed: