Bathroom sinks, kitchen sinks and shower drains can over time start to drain slower due to an accumulation of soap fat and hair with other debris. The quicker you notice it is slow draining the better. before the water backs up into the sink, bath or shower. this is the time to get the drain cleared before it becomes a more serious problem.
If the slow draining is localised to one sink the bath or shower, sometimes it can be easily solved by removing hair clogged around the waste trap in the bath, basin or shower tray by checking for any foreign objects like soap or debris trapped on the strainer. an easy way of clearing this type of drain blockage is to use a piece of wire to hook out the debris. When you have moved all the debris, it is advisable to run very hot water and some bleach or shop bought drain cleaner down the drain. this will help clean any drain blockage further down.