Influenza (flu) is a disease that affects people of all ages and in all regions of the world. The common symptoms of flu include a runny nose, fever, aches, chills, headache, cough and feelings of fatigue and weakness. The disease often comes on quickly. Although the symptoms are similar to the common cold, they are often much worse with flu. Some patients suffer greatly, describing the symptoms as ‘agony’, like being ‘hit by a freight train’ and even ‘I felt I was going to die’. In most people a case of flu lasts for 3–5 days, although a cough, tiredness and feeling unwell may last for up to 2 weeks [1, 2].