This is perhaps one of the most common reasons for a runny nose and there are many possible causes. Dust mites are an obvious trigger. Others include pollen and pet dander, perfume and work-related factors such as dust or latex. House dust mites inhabit every home, and although harmless, often peak in numbers in spring and autumn.
Sort it: Your GP can arrange certain allergy tests to try to pin down what your individual trigger is, although these cannot identify every possible cause.
2. Excessive dairy intake
This is trickier to diagnose, but many people with runny noses report improvement when they cut down on or stop consuming dairy products. Milk allergy does exist, with the problem being an allergy to casein (the protein in cow’s milk), which in turn causes increased histamine and excessive mucus production. Usually diagnosed when young, it can develop later in life.
Sort it: Skin or blood tests can help with the diagnosis. Try reducing your intake of dairy products.
3. Acid reflux
Unless you’re very lucky, you will have experienced heartburn or acid reflux from time to time, which occurs when acid leaks from the stomach into the gullet. What you may not know, is that acid can sometimes get as high as the back of the throat and the back of the nasal airways without any burning symptoms. This is known as ‘silent’ reflux. It can cause a persistent running nose - the symptoms of which are often mistakenly attributed to a cold or hay fever.
Sort it: Simple antacid treatments usually cure this.
4. Gut problems
If your gut biome balance is out of proportion, you may develop fungal gut infections that trigger a reaction and increased mucus production.
Sort it: Taking high-quality probiotic supplements and including immune-boosting foods such as garlic and rosemary in your diet can help reduce or prevent this occurring.
Smoke is highly irritating to the body in many ways, especially in the upper airways of the mouth, nose and throat. This can cause inflammation of the nasal passages and trigger a persistent runny nose. You don’t even have to be a smoker yourself - living with someone who puffs away can be enough to trigger a runny nose.
Sort it: Quit smoking now.