As innocuous as many winter ailments are, it is vital to be aware of the signs and symptoms that might indicate something more sinister. Suspicion of the following conditions warrants immediate medical attention:

• Meningitis can cause similar symptoms to flu, particularly in children. Signs that suggest more serious infection include a non-blanching rash, high fever, vomiting, high-pitched screaming, floppiness, bulging fontanelle, convulsions, stiff neck, photophobia, severe headache and/or confusion
• Pulmonary embolism can cause cough. It may be accompanied by breathlessness of acute onset, chest pain, haemoptysis (coughing up blood from the respiratory tract), tachypnoea (>20 breaths per minute), tachycardia (>100 heart beats per minute), and chest crackles. It is more common in individuals who have recently had surgery or a period of immobility, cancer patients and those with a history of deep vein thrombosis
• Pneumothorax can cause cough, alongside tachycardia, sudden onset chest pain and breathlessness, and can quickly lead to collapse. Risk factors include smoking, respiratory disease, chest wall trauma and previous pneumothorax
• Aspiration of a foreign body can cause a cough to start abruptly and is likely to be accompanied by distress and stridor (high-pitched wheezing).