It may seem odd that your nose can clog up and run at the same time, but these are the results of your body's natural defenses to a cold or allergies. The allergens or cold viruses cause your immune system to produce antibodies. The reaction between allergens and antibodies gives off histamines, which cause the capillaries in your nose to swell, resulting in congestion. Histamines also trigger the runny nose effect. Most commercial cold remedies contain decongestants to reduce the swelling, and some also contain antihistamines to dry up the runny nose. While these may relieve the symptoms temporarily, they don't have any effect on the cause of the condition. There is still no cure for the common cold, but an ear, nose, and throat specialist should be consulted if you suspect that the cause of your condition may be allergies. An otolaryngologist (OH-TOE-LAIR-IN-JOLLA-JIST) can help you find the cause of your allergy, then implement a program to reduce your sensitivity to it, or help you avoid that particular allergen in the future.