<P> Rhinorrhea is characterized by an excess amount of mucus produced by the mucous membranes that line the nasal cavities . The membranes create mucus faster than it can be processed , causing a backup of mucus in the nasal cavities . As the cavity fills up , it blocks off the air passageway , causing difficulty breathing through the nose . Air caught in nasal cavities , namely the sinus cavities , can not be released and the resulting pressure may cause a headache or facial pain . If the sinus passage remains blocked , there is a chance that sinusitis may result . If the mucus backs up through the Eustachian tube , it may result in ear pain or an ear infection . Excess mucus accumulating in the throat or back of the nose may cause a post-nasal drip , resulting in a sore throat or coughing . Additional symptoms include sneezing , nosebleeds , and nasal discharge . </P>
<P> Rhinorrhea is characterized by an excess amount of mucus produced by the mucous membranes that line the nasal cavities . The membranes create mucus faster than it can be processed , causing a backup of mucus in the nasal cavities . As the cavity fills up , it blocks off the air passageway , causing difficulty breathing through the nose . Air caught in nasal cavities , namely the sinus cavities , can not be released and the resulting pressure may cause a headache or facial pain . If the sinus passage remains blocked , there is a chance that sinusitis may result . If the mucus backs up through the Eustachian tube , it may result in ear pain or an ear infection . Excess mucus accumulating in the throat or back of the nose may cause a post-nasal drip , resulting in a sore throat or coughing . Additional symptoms include sneezing , nosebleeds , and nasal discharge . </P>
where does the fluid come from when you have a runny nose
where does the fluid come from when you have a runny nose
the mucous membranes that line the nasal cavities
the mucous membranes that line the nasal cavities