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  • Writer's pictureDr. Brian Lum

7 Reasons Why You Have Sinus Congestion In Winter

Updated: Feb 2, 2022

Many assume that sinus congestion comes from either a virus or seasonal allergies, but there can be many causes of chronic sinusitis.

So what is going on when you have allergy-like symptoms in the depths of winter? And what is going on when this doesn't last a few days - but for months?

Here are some less-than-obvious explanations to a common occurrence - and some simple ways to fix them!

A snowy landscape. text overlay saying Why you have sinus congestion in winter

1. Fungal Infection

While most cases of sinusitis due to infection are either viral or bacterial in origin, fungal infections are also common.

Antibiotics are frequently prescribed in cases of severe sinusitis (regardless of the cause). While sometimes necessary, antibiotics wipe out beneficial bacteria and can give a fungal infection a stronger foothold. This is a way that many fungal infections turn chronic.

It is vital to know the source of your symptoms. The wrong or inadequate treatment can make you sicker for longer. In rare cases, there are certain fungal infections that are invasive and can be potentially life threatening.

If you just assume you have a chronic viral infection be sure to go to a functional medicine doctor to rule out other possibilities and properly diagnose the infection.

Proper diagnosis and targeted treatment can be the difference between months of symptoms and a rapid recovery.

2. Food Allergies and Sensitivities

If you read this blog, you'll notice how often I mention food allergies and sensitivities as a possible cause of a wide range of symptoms. That's because they are incredibly common and frustratingly under diagnosed.

histamine releasing avocados
Even 'healthy' foods like avocados, potatoes and onions can be food allergies

A primary symptom of a food sensitivity is chronic sinusitis. Sometimes, it's the only symptom.

Pay attention to how you feel when you eat certain foods. If you get congested after eating dairy or gluten, for example, then you may have a sensitivity.

The best way to see if you have a low grade sensitivity is to do an elimination diet.

Remove suspected foods completely (no cheating!) for at least 4 weeks and see how you feel.

Many people who have sensitivities report feeling renewed energy, weight loss, mental clarity and better sleep once they have removed their sensitivities.

3. Environmental Allergens & Toxins

With winter comes cold weather and closed up houses. Unfortunately, the toxins inside your house can be worse than outdoor pollution from a big city.

These indoor toxins are caused by the off-gassing of toxic furniture, artificial fragrances, air fresheners, candles and conventional cleaners.

Vacuum and dust regularly, and on warmer days, open up the windows to get some much needed air circulation.

You can also get a good quality air filter as well as a few houseplants to help you keep the air clean.

4. Its Really, Really Cold

Frigid temperatures, as well as wild swings in weather, place a strain on your immune system.

a snowy forest
Extreme temperatures and weather shifts can be hard on your immune system

Many people have underlying infections like staph, strep and various strains of fungus in their sinuses.

These infections are low-grade enough not to cause symptoms unless the individual is under a biochemical strain like grief, stress, sleep deprivation, nutritional deficiency or extreme cold or heat.

In winter, we are less active and are subject to different stressors - this can make latent infections stronger and can start causing symptoms like sinusitis.

As with any symptom, don't assume. If you have had long term sinus congestion it is important to rule out potential causes with a doctor.

5. Its Too Dry or Too Humid

In winter, our heaters are working overtime - which can lead to very dry air. Dry air can inflame the sinuses causing cold-like symptoms of congestion.

Humidifiers can be a great solution - but don't go overboard. Humidity over 50% can lead to mold growth (which is yet another thing that can cause chronic sinusitis).

Run a humidifier with distilled water and follow all cleaning instructions to ensure you are circulating clean air.

6. Nutrient Deficiency

There are a few vitamin deficiencies that are very common in the general population - and even more common in those who have chronic conditions or who are often sick.

Vitamin A is an often overlooked vitamin vital for vision, reproductive health and immune system function. Get a blood test to assess your values as too much of this vitamin can be toxic. Also, don't assume that just because you eat lots of carrots that your vitamin A levels must be ok - many people genetically do not convert beta carotene (found in carrots and other foods) into a form your body can use efficiently.

a beach full of sunlight
Sunlight, a source of vitamin D, is in short supply in winter

Vitamin D is frequently cited as being important for immune function and for protecting against disease but most people are taking the wrong dosage or the wrong form.

Get a blood test to see if you are deficient, this (and if you have any health conditions) will determine the form and dosage of vitamin D you need to take.

Zinc is another common deficiency during winter and in many sinusitis sufferers. As with other nutrients, dosage is key - too much zinc can cause nausea and vomiting.

As always, your exact dosage and form should be determined by a functional medicine doctor who knows your medical history, conditions and can replete your deficiencies based on your most recent testing.

7. Microbiome Dysbiosis

Gut health seems to be linked to everything from the clarity of our skin to the speed at which we lose weight. What is less well known is just how much our gut health has to do with our respiratory health.

Our microbiome is not just in our digestive tract, it is in all of our mucus membranes.

an impaired microbiome full of infection
Food poisoning, poor diet, stress, and antibiotic use can all cause gut dysbiosis that can cause chronic sinusitis.

Infections like staph and candida are often present in the sinuses and in the intestinal tract.

A process called 'reseeding' illustrates just how interconnected everything is.

Reseeding happens when infection in the gut is killed by antibiotics but infection in the sinuses is still present.

Nasal drip of infectious fluid is drained down the throat where it 'reseeds' the infection into the intestinal tract.

This process creates a cycle of infection that can have patients retaking antibiotics over a long period of time.

In cases like this, I always run a comprehensive stool analysis to determine what kind of infection is causing the problem.

Treat the Whole Body, Not Just The Symptom

When we talk about 'sinus problems' it's hard not to compartmentalize the sinuses in to their own little bubble in the body.

The reality is that our bodies function as adaptive entities that are constantly being shaped by our genes, environment, food, people and the pathogens that surround us.

If you have a chronic sinus problem that you can't seem to get to the bottom of, it's important not to dismiss it.

Once the cause is found, usually chronic sinus issues can be resolved quickly and naturally.

If you would like to speak to me to ask questions about functional medicine, chronic illness or how I can help you, please schedule a Free 15 Minute Consultation or call or text my office at 913-728-5291.

My clinic offers functional medicine appointments as well as manual chiropractic treatments. I do online consultations for those out-of-state or outside of the United States.


If you think that you may have a medical emergency, call your doctor or 911 immediately.  No action or inaction should be taken based solely on the contents of this information. Nor should you ever delay seeking medical advice or treatment due to the information contained on this Website.

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