You really need to determine whether the moisture is from outside or inside the house. But from an external point of view, you should have an effective Damp Proof Course (DPC) near the bottom of your living room walls which should prevent the moisture from rising up the walls.

Sometimes, this can be bridged - typically (over time) through a build up of soil from the garden or by a bit of thoughtless DIY, where a path around the outside of the house has been laid, raising the external level above the DPC.

Another possible cause is if your external walls are rendered or pebbledashed over the brickwork - again this gives the damp an opportunity to cross the DPC.

We've just had one of the wettest years on record with many properties being flooded for the first time, so I suspect there will be plenty of people experiencing damp problems - especially when the surrounding ground rises above the property.

Initially, it might be useful to have a word with your neighbours to see if they're experiencing the same and (if you can see your DPC) have a quick check that nothing obvious is bridging it - else I would suggest you locate a reputable builder to investigate further.

And as shzl400 has quite rightly pointed out, condensation inside the house can also make the walls damp - when I was having some building work done, my builder discovered that the skirting boards were damp - I thought it was rising damp from the ground below and got a damp proof specialist in to take a look. But he diagnosed condensation from inside the house.