overheating can be caused by too many reasons, low coolant level, clogged or leaked radiator, worn-out radiator cap, thermostat not functioning, radiator fan not operating properly, faulty head gasket, water body malfunction, or too much air in the cooling system etc etc. if you continue to run your car with faults such as mentioned above it can cause serious damages to the engine like a blown head gasket, cracked cylinder head or even a cracked engine block!
A stitch in time, saves nine! its always a good idea to service the radiator once in a year at least, even when its working properly in order to avoid any mishap like overheating!
get the radiator checked first, there should be no leakage in it, & it should not be clogged with dirt/ rust etc.. use a better coolant, improper coolant can also cause overheating problems, inspect the radiator cap and see if all its seals are intact, radiator cap maintains pressure within the cooling system and if not in a proper state can cause air to enter the system which can also lead to bubbling in the radiator & overheating! get the thermostat checked, head gasket should also be checked, if the car has previously got involved in over heating then this might have damaged the gasket.. its also a good idea to change the engine oil when you change the gasket since extra high temperature might have affected the viscosity & characteristics of the oil..
there can be so many factors causing the over heating, its better to get everything thoroughly inspected!