• Acute cough is the main feature of a cold and flu. It is not unusual for a cough to persist for three to four weeks (when severe it is often called acute bronchitis). In most patients there is no need for referral or antibiotics
• Sore throat is commonly associated with cold and flu. Most cases resolve within a week, so symptomatic treatment should be advised. However, referral may be necessary if the patient is very unwell or has difficulty swallowing. Patients on chemotherapy, disease-modifying antirheumatic drugs and carbimazole should be referred urgently. Those with no cough or cold symptoms are more likely to have a bacterial infection, so may need referral if they are ill
• Earache is very common with a cold and flu in children. In most it gets better within three days to one week and no treatment other than pain relief is needed. More severe cases are defined as acute otitis media. Persistent high temperature, particularly in younger children, may be an indication for referral. Any child who appears particularly unwell, infants (under two years), or when there is discharge from the ear merit referral
• Sinusitis is common and usually presents with facial pain and congestion. Toothache and fever may also be present. Symptoms typically last for two to three weeks and are usually self-limiting, so most cases are treated symptomatically. Those patients with persistent symptoms, rapid deterioration, or who are systemically unwell should be referred. Purulent nasal discharge, particularly if unilateral, may also be a reason for referral
• Pneumonia is most commonly associated with flu rather than a cold. A productive cough is the major symptom and is usually accompanied by fever, muscle aches, sweats, wheeze, shortness of breath or chest pain. The elderly are more likely to acquire pneumonia and may present with weakness, malaise and confusion. Patients with prolonged cough or other conditions such as diabetes and heart disease, or if they are old and frail, should be referred for further assessment.

Patients who are very unwell, or where there are concerns about more serious illness, need urgent referral. There should be a lower threshold to refer to primary care or A&E those patients on immunosuppressants (often for cancer or arthritis, or following a transplant), corticosteroids, or with diabetes. If flu is suspected in these people, early referral may be warranted for assessment and also consideration of antiviral treatment.

Certain clinical signs warrant emergency admission in ill patients. These include a respiratory rate higher than 30 breaths per minute, tachycardia in excess of 130 beats per minute, altered consciousness and significant respiratory effort, particularly if accompanied by exhaustion.