Sinusitis is the inflammation of the lining of the sinuses, caused by a viral or bacterial infection. You have four sinuses in your head and your sinuses open up into the cavity of your nose and help control the temperature and water content of the air reaching your lungs. There are a number of ways your sinuses can become inflamed or blocked, but the most common cause is a viral infection – otherwise known as flu or a cold. On the show, we’ll talk about your sinuses, why they become blocked, how to prevent them from inflammation and what to do to treat sinusitis. As it is our health show, our expert will be on hand to answer any other health-related questions.