Dr Bernadette Carr answers your question on cold sores and cystitis

I never had a cold sore until two weeks ago — it has now cleared up, is there anyway to prevent another one?

Cold sores can be very tender and painful. At the primary stage, it is asymptomatic but may reactivate later in life.

They usually resolve without any treatment but this can take seven to 10 days and begin with an itch or tingling, this can last from several hours or up to a day.