Children are not born with a knowledge of how to blow their noses.
Breathing in and out is an instinctive ability; blowing in and out, either through the mouth or nose, is a learned behaviour.
Teaching a toddler or pre-schooler how to blow their nose turns out to be quite a challenge – partially because it doesn’t occur to most of us that we are going to need to, and partially because we don’t think about it until our child has a nose full of gunk! Then we just expect that blowing their nose will come naturally.
The best place to start is not by focusing on the nose, but the mouth. And, the best time to start is when the child is well. Once the idea of blowing through the mouth is established we can progress to blowing through the nose. And, as with most child learning, it happens most easily if we make it fun.
To get your child to practice blowing through their mouth, use the tradition of blowing out birthday candles, letting your child blow out the candle and re-lighting as necessary. Another good game is holding a piece of tissue about 20cm in front of your child’s face and get them to move it by blowing. Blowing up balloons is another good practice.
Once your child has mastered blowing through their mouth, move on to blowing through their nose. Repeat the tissue blowing exercise, but this time with the tissue much closer to the face. Have our child take a deep breath and then try to blow a tissue using their nose (only exercise with very light objects – such as tissues or feathers – so as not to put too much pressure on nasal cavities and ears). You may need to hold your own index finger up and down on their lips, as if you are telling them to ssssh, to encourage them to blow through their nose. It may help to close off one nostril and blow through one side at a time. This seems to help some children feel the air move through their nose while keeping their mouth shut, which is the key – and the hardest concept for children to grasp.
Practicing over and over again is the key to getting your child comfortable with blowing their nose.