No runny noses are not contagious and just because someone else has a runny nose in your house or around you it doesn't mean that you will catch the runny nose.
You can however catch a cold or flu virus that a person has when they have the runny nose so then you may experience a runny nose as a result of catching that cold or flu virus.
But it's not because of the runny nose since runny noses are not contagious.
Some people even get runny noses when they are out in the cold weather or just due to allergies which then leads to the runny nose.
In those cases those runny noses are not caused by any virus so you cannot get a runny nose from someone else because a runny nose is not contagious.
You can help stop a runny nose by using a Net Pot to clean your nasal passages out and take a steamy shower or use a humidifier to help keep your nasal passages moist.
Using a nasal spray is also a good thing to help runny noses.