On the assumption that it's actually Hibiscus rosa sinensis (houseplant) and not an outdoor form, this plant hates draughts and won't tolerate temperatures below 55 deg. F. If its been moved to your home for you to look after, (i.e., taken outside and then into yours) a brief interlude of cold air might have been enough to have upset it.

Thanks for this info, how will I know if it's a Hibiscus rosa sinensis (houseplant) or not? I checked the plant but there's no label, may have got lost in the move.... I seem to remember it having a name, I'll check with my mum and see if she knows... or even better if we can find the missing label anywhere.... I have been "given" it as there's no room for it in her house anymore... Have taken a photo of it and maybe someone will can tell whether it's indoor or not???

Ooops sorry have uploaded a couple of the garden Pics first instead of the Hibiscus one.... but I guess it shows what the weather here is like!

I've got a couple of Hib. rosa sinensis and my first thought is that yours seems to be in a very small pot for the size of plant. My other thought is that it's right by a radiator in the photo, so it could well be too hot and dry. You could try placing the pot over a tray of moist gravel to increase humidity. Otherwise, the plant looks pretty good to me - maybe it's just naturally shedding some old leaves, as teh leaves on evergreens don't last for ever.

Does look like rosa-sinensis, though the leaves look a bit large - they should be up to 3 inches long, and its hard to tell the exact size from the photo. You can cut it back now if you want to make it a bushier plant (best time for this is late winter).I'd agree with Sid about repotting.

Thanks Bamboo... will try repotting then see if it recovers before cutting back...or should I do it the other way round???

You either cut it back now or next winter - now's the time, I'm afraid! I'd cut it back and then repot in spring, later on.

Thanks Bamboo