Idiopathic pulmonary fibrosis (IPF) is a progressive scarring condition of the lungs the cause of which is unknown.There are currently no effective treatments for IPF and the condition tends to cause progressive disability and death with an average survival of 3.5 years from diagnosis. The condition is responsible for the deaths of 4000 people per year in the UK. At present the definite diagnosis of IPF rests on the identification of a specific pattern of fibrosis when a section of fibrotic lung tissue is examined under a microscope. Unfortunately, the process of obtaining a lung biopsy requires an operation and is not with out risk. The investigators hope to identify specific markers in the blood and lungs of patients with IPF that will enable the condition to be diagnosed without biopsy. Furthermore, the investigators hope to identify indicators(biomarkers) that will predict which patients have more aggressive and progressive disease and also to identify biomarkers that might be useful in identifying a response to treatment and might therefore be used in future clinical trials in IPF. As well as looking at markers in the blood and lungs the investigators also plan to assess the use of daily home lung function measurement and a computerised technique for analyzing lung sounds to see if these are investigations that are able to predict the development of worsening lung fibrosis.