curling up, or curling down? and I assume you mean fanleaves.

Curling up COULD be heat, it can also be a lack of humidity, but if their curling and drying, it could be either of those, or a deficiency (post pics)
Curling down COULD be too much humidity, lack of light, lack of nutrients, or just a sad plant.

Either way, post pics, that will help us help you more.