It is estimated that around 20% of people in The UK suffer from allergic rhinitis. The condition is caused by an overactive immune system, whereby it mistakenly reacts to allergens in the same way that it would an infection. As a result, when harmless allergens enter the nose, the body overreacts and starts to produce extra mucus.
It is this overreaction that leads to symptoms, such as sneezing, congestion, and a runny nose. It still isn’t fully understood why some people’s immune system reacts this way. However, allergic rhinitis often runs in families, so genetics is believed to play a role.
In most cases, allergic rhinitis doesn’t cause any serious complications, though the symptoms can be extremely frustrating and inconvenient. In rare cases, allergic rhinitis can lead to sinusitis or a middle-ear infection.