Here's what you need to know about whether humidifiers can help relieve nasal congestion. Humidifiers can help combat troublesome symptoms that arise in dry seasons, but can humidifiers help relieve nasal congestion? Humidifiers work by adding moisture to the air. You pour water into the humidifier's reservoir and it outputs a gentle, filtered mist. The relative humidity in your home — meaning the density of water vapor relative to the temperature in a space — should be kept between 30% to 60%, according to the American National Standards Institute (opens in new tab). If the humidity level drops below this, it can trigger troublesome symptoms such as dry skin, dry sinuses and dry eyes. The science currently hints that humidifiers may help relieve congestion in some cases, but more research is needed to know for sure. If you have any concerns or specific questions, especially if your congestion isn't going away, speak to your doctor. What causes congestion? Congestion, or "stuffy nose," is defined as an excess of fluid or mucus in the nasal passages that causes them to swell, according to Dr. Jamie Rapacciuolo (opens in new tab), a family medicine physician at ChristianaCare Primary Care in Wilmington, Delaware. She told Live Science that congestion is most commonly caused by a physical barrier, such as a mucus buildup, or inflammation in the nasal passages. "Inflammation can develop in multiple ways, such as swelling of [blood] vessels, increased fluids that have a thicker texture within the nasal passages, and swelling of the tissues on the inside of the nose," she said. "All of these causes can result in a smaller passage route for which air to move through when breathing." Essentially, anything that irritates the nasal passages, including excessive dryness, can cause congestion. Although dryness isn't the only possible culprit, it can be a part of the issue if it causes the tissues on the inside of the nose to swell. Do humidifiers help with congestion? If dryness can cause congestion, it’s easy to assume that a humidifier might relieve congestion by releasing moisture into the air. But it isn't quite so simple "In general, the presence of moisture helps reduce the thickness of secretions and allows the thinner fluid to move more freely through the smaller passageways" in the nasal passages, Rapacciuolo said. "But while there is a belief that cool-mist humidifiers can help with cough and congestion, the evidence does not unequivocally support this belief. More research needs to be completed to validate whether humidifiers can help with congestion." Warm-mist humidifiers also release water into the air, but the water is heated inside the appliance beforehand. While this type of humidifier is just as effective for changing the humidity in the room (and therefore potentially easing congestion), cool-mist humidifiers are generally considered safer, especially for those with children, because there is no heat involved. So while using a humidifier may reduce some of the stuffy sensation, as Rapacciuolo pointed out, there still isn’t concrete evidence to suggest it helps ease congestion. What are the risks of using a humidifier? For the most part, adding a bit of humidity to your indoor environment shouldn’t hurt, but there are a few key precautions to keep in mind, especially if you are experiencing respiratory symptoms. "A collection of water, and growth of both bacteria and mold, can occur within humidifiers and other machines that utilize water if these devices are infrequently cleaned," Rapacciuolo said. "You should change the water in your tank every day. When not in use, keep the surface parts of the humidifier dry," she said. "If your humidifier has a filter, be sure to replace the filter as directed by the manufacturer. Depending on the area that your humidifier is located and the duration of time that it is in use, you also may consider changing the filter more frequently to protect you from congestion." Additionally, if an environment already has too much moisture, using a humidifier could cause some symptoms to worsen. "In areas with too much humidity, symptoms of an illness or condition can worsen," Rapacciuolo said. "Areas with too much humidity will also feature surfaces that carry a continuous layer of moisture that propagate the growth of both bacteria and mold. This phenomenon can trigger allergy symptoms and exacerbate lung illnesses such as asthma." Source
