It is more than uncomfortable and inconvenient for an infant to have a stuffy nose--babies under 6 months breathe through their noses, so congestion can interfere with feeding. There are simple ways to alleviate congestion and help your baby breathe more easily.
Using a bulb syringe is very simple. A bulb syringe looks like a short, fat turkey baster. Squeeze the fat end before placing it inside the infant's nose. Then, releasing the bulb, use the thin end to suck mucous from your baby's nose. He won't like it and may try to pull away, so be sure to have his head safely secured.
Saline drops in the infant's nose can be soothing. Drops can also be used before using the bulb syringe to loosen secretions and make mucous easier to suction. There are commercially prepared solutions or you can make your own. According to the University of Michigan Health System, a saline solution can be made using 8 ounces of tap water, 1/2 teaspoon of non-iodized table salt and a pinch of baking soda. It is important that the solution is made fresh every time it is used to prevent bacterial growth. A smaller batch can be made by halving or quartering the recipe.
Vapor or mist in the air using a vaporizer works well for an infant with a stuffy nose. Cool mist vaporizers are safer because they are less likely to cause injury if tipped. Warm vaporizers also grow bacteria more quickly and have to be cleaned more often. Another way to get mist to your baby's nose is to take her into the bathroom and run the shower on hot. The two of you can sit outside the shower and take in the mist, which will help relieve her stuffy nose.