When the weather starts to get cold, many people experience allergy flare-ups, including nasal congestion, runny nose, coughing, sneezing, or increased difficulty breathing, even though the weather seems better and fresher than other seasons. This makes many wonder, “Why do allergies get worse in winter?” This article will help you understand the causes in a simple way, along with tips to take care of yourself for clearer breathing every day.
Why do allergy symptoms flare up during winter?
- Dry air causes the nasal mucosa to become easily irritated. Cold air usually has low humidity, causing the nasal mucosa to dry out, crack, become irritated, and more sensitive to allergens, leading to nasal congestion, sneezing, and clear runny nose, which in some cases can make the nose more prone to infection.
- Rapid temperature changes are a major trigger for allergies. From a warm room → cold air → air-conditioned room, sudden temperature changes cause the bronchi and nasal mucosa to contract, resulting in
- immediate runny nose
- frequent sneezing
- increased coughing
- chest tightness in those with respiratory allergies or asthma
- Spending more time indoors In winter, many people close windows, turn on air conditioning, and use heaters more, increasing exposure to dust mites and mold.
- Using blankets Winter blankets or sweaters that have not been washed for a long time or stored for a long time often have higher dust mite accumulation. Using them immediately causes the body to respond with allergy flare-ups.
- Respiratory infections in winter Winter is a season when viruses spread, and some symptoms resemble allergies. Infections weaken the nasal mucosa, making existing allergies more likely to flare up.
- Cold weather reduces immune system function When the temperature drops, the body redirects blood flow to vital areas to maintain temperature, weakening the nasal mucosa’s defense system and making it more sensitive to allergens such as dust, smoke, or odors than usual.
Common allergy symptoms in winter
- Nasal congestion, clear runny nose
- Repeated sneezing
- Itchy nose, itchy eyes, watery eyes
- Dry cough
- Chest tightness, wheezing (in those with asthma)
- Easily fatigued, reduced sleep quality
How to manage allergy symptoms in winter for more comfort
- Reduce dust in the bedroom Wash bed sheets, pillowcases, and blankets every 1–2 weeks. Avoid using carpets. Use dust mite covers and regularly vacuum with an air purifier that has a HEPA filter.
- Open windows for ventilation at least 20–30 minutes a day to reduce mold, dampness, and dust accumulation in the room.
- Avoid sudden temperature changes Before leaving an air-conditioned room, pause for a moment or wear a mask to protect against the cold in the morning.
- Maintain proper humidity in the house Ideal humidity is 40–50%. If the house is too dry, use a humidifier.
- Rinse your nose with saline to reduce allergen buildup, decrease nasal discharge, and help clear breathing.
- Keep allergy medication at home Only those recommended by a doctor, such as antihistamines or steroid nasal sprays, but do not use continuously without consulting a doctor.
When should you see a doctor?
You should see a doctor if you have any of these symptoms
- Severe nasal congestion causing difficulty breathing
- Chronic cough lasting more than 2 weeks
- Chest tightness, difficulty breathing
- Thick green nasal discharge or fever
- Frequent flare-ups that disrupt daily life
- Suspected dust mite, mold allergies, or allergies requiring further testing
In an era of fluctuating weather and increasing pollution, managing “allergies” is not just about treating symptoms when they occur but involves proactive care (Preventive Health) combined with adapting behaviors to changing environments, whether it’s dry air, PM2.5 dust, or rapidly fluctuating temperatures. Being aware of your triggers, using technology to monitor air quality, and planning prevention early will greatly help control symptoms.
If allergy symptoms frequently flare up and affect daily life, seeing a doctor for personalized allergy care (Personalized Allergy Care) will help plan appropriate treatment and prevention in the long term, allowing you to live comfortably and safely during the winter season.
Dr. Sasipa Saengkanjanavanich
Director of Allergy and Asthma Center
Phyathai 2 Hospital
