How long has your nasal drip been present? You mean it occurs with the tongue swelling or you just have this condition for a long time? If the two conditions occur at the same time, it is most likely to be caused by some allergic reactions. Using antihistamines such as benadryl would help. If the tongue swelling occurs recently and the nasal drip is chronic, the tongue swelling may be due to incidental bites by yourself, glossitis, hot or spicy foods, excessive consumption of alcohol, or tongue infections.