My 94 civic dx always use alot of antifreeze coolant. Every three days, i always have to pour some in and it overhea too. Can this be the radiator or the thermostat?

 

Thermostat could be stuck closed causing it to overheat, causing coolant to leak from somewhere... make sure your oil isn't thick and milky brown (coolant + oil), that means your head gasket is blown. Do a compression check to be certain. If that comes out good, probably just have a leak somewhere in the system, good luck finding that...

 

Make sure your fan is kicking on. If its not, jump the fan to your battery to see if it comes on. If you jump the fan and it doesnt work its your fan, if you jump it and it comes on it could be your thermoswitch or relay. It wouldnt hurt to do a flush of your radiator/system.