Most colds need no medical care and resolve on their own. You should arrange a review if symptoms persist beyond about 10 days without improvement, if you initially get better and then worsen, or if you develop a high or persistent fever.
Other reasons to seek advice include severe headache or facial or sinus pain, an earache, a sore throat that is severe or worsening, or symptoms in someone who is pregnant or has a long-term condition such as asthma, COPD, diabetes, heart disease, or a weakened immune system.
Go to urgent care or call your local emergency number for shortness of breath or trouble breathing, chest pain, coughing up blood, confusion, bluish lips, or signs of dehydration. For infants and young children, seek help earlier and more readily.