People often assume it’s just cold when they keep sneezing in winter. However, real culprits are frequently winter allergies, says Dr Ankur Bambhania. "A cold runs its course but allergies can continue indefinitely," he added. Allergies don't cause fever/ systemic fatigue like colds do, says Dr Ravi Kumar, adding "Cold mucus is thicker/yellowish, while allergies usually produce clear discharge."