" Allergies and a cold share many symptoms – runny nose, cough, congestion. What are the main differences to help tell them apart? The physicians at AFC Urgent Care Waltham can help diagnose any upper or lower respiratory illness you may have. From there, treatment will be provided to help you feel your best. Allergy Symptoms Allergies happen when your immune system has a reaction to an unknown substance, such as pollen. Your body then tries to ...