Damp in Property

Tenancy Types and Management

I own a property that was bought from the current tenants in around 2008.

They claim that there is a damp problem in the property that has arisen in the last few years. One area is in an upstairs bedroom below the window where their conservatory (erected before we bought the house, meets the house. I have asked them to get in touch with conservatory company as this appears to me a fault of theirs.

Now the tenant has returned to me saying that there is damp else where and that her doctor has advised her to move out.

My question is, where do I stand legally on obligations to fix something that is the fault of contractors employed by the tenants when they were previous owners and also, should I ask to see a medical report before ripping apart the plaster?

Many thanks

CJ