My Mums coughing has been getting worse the past few days and I'm really worried. I've taken her to the doctors three times in the past two months. Sometimes there is blood in the phlegm on tissues and on her duvet. She had a chest xray two weeks ago and nothing showed up. The doctor keeps saying her chest sounds clear but she sounds dreadful, especially in the mornings. Its obviously quite debilitating for her. I've suggested it could be her new blood pressure tablets as they can cause problems so she has temporarily come off them but no change after two weeks as yet. I tried to get another appointment with the doctor yesterday but as usual they were full. I asked for a doctor to phone me. He said he will refer her to a respiratory specialist. In the meantime, I'm wondering if it would be worth buying an air purifier in case its an allergy to something. Does anyone have any experience of these please? Argos sell a few so I thought I might purchase one today, mid range priced one, as I must do something to try and help Mum.