Why Immunity Drops in Winter: Symptoms, High-Risk Groups & Doctor-Recommended Prevention

Have you ever wondered why more people fall sick during winter? Why do colds, coughs, throat infections, and fatigue suddenly seem so common when the temperature drops? Winter affects the body in many ways, and one of the biggest impacts is how it weakens our immunity.

To help people understand this seasonal drop in immunity and how to stay protected, Dr. V Deepak Kumar, Senior Consultant Physician & Diabetologist of Malla Reddy Narayana Hospital, Hyderabad, throws light on the key reasons behind weakened immunity in winter and shares doctor-recommended tips to stay healthy.

Why Immunity Drops in Winter

Winter challenges our immune system due to a mix of physiological, environmental, and lifestyle factors, not simply because the weather is cold.

1. Weakened Nasal Defences: Cold air lowers the temperature inside the nose, slowing down immune cells that normally fight viruses. This makes it easier for viruses to enter the body and multiply.

2. Dry Air Affects Natural Protection: Low humidity, both outdoors and indoors due to heaters, dries out the nose and throat. When these protective layers lose moisture, they cannot block germs effectively.

3. Reduced Sunlight & Low Vitamin D Levels: Shorter days mean less sunlight exposure, leading to reduced Vitamin D production, which is essential for strong immunity. Low Vitamin D makes the body less effective at fighting infections.

4. More Time Indoors: People naturally spend more time inside closed rooms during winter. Poor ventilation and close contact increase the spread of viruses like the flu, cold, and RSV.

5. Viruses Survive Longer in Winter Conditions: Cold and dry environments allow many viruses to stay alive longer in the air, making infections easier to catch.

Symptoms of Weakened Immunity

You may have low immunity if you experience:

High-Risk Groups During Winter

Certain people are more vulnerable to winter infections and complications:

Dr. V Deepak Kumar, Senior Consultant Physician & Diabetologist of Malla Reddy Narayana Hospital, Hyderabad,

Doctor-Recommended Prevention Tips

Doctors emphasize that “immunity drops” and supplements alone are not enough; a healthy lifestyle is the real protector.

1. Stay Updated on Vaccinations: The annual flu vaccine is one of the most effective ways to reduce winter infections, especially for high-risk individuals.

2. Practice Good Hygiene: Wash hands often, use sanitizer when needed, and avoid touching your face. Good hygiene breaks the chain of infection.

3. Eat a Balanced, Immunity-Boosting Diet:  Include Vitamin C foods like oranges, lemons, and bell peppers. Other Vitamin D foods like eggs, fortified milk, fatty fish. Zinc-rich foods like nuts, seeds, and legumes. A colourful plate boosts natural immunity.

4. Stay Hydrated: Dry winter air dehydrates the body faster than we realise. Drink water, warm soups, and herbal teas to keep your mucous membranes moist and healthy.

5. Sleep Well: Your body repairs itself during sleep. Aim for 7–9 hours to support immune cell production.

6. Stay Active: Light exercises, walks, yoga, or home workouts improve blood flow and strengthen immunity.

7. Manage Stress: Chronic stress suppresses immunity. Practice breathing exercises, meditation, journaling, or simple relaxation.

8. Wear Weather-Appropriate Clothing: Keep your body warm, especially hands, feet, and head, to avoid sudden temperature drops.

9. Maintain Clean Indoor Air: Use a humidifier, open windows for ventilation, and avoid overcrowded rooms when possible.

10. Consider Supplements with a Doctor’s Guidance: Vitamin D, Vitamin C, zinc, or probiotics may be recommended if your diet lacks essential nutrients.

Conclusion

Winter brings beautiful weather, celebrations, and cosy moments, but it also brings challenges for your immune system. By understanding why immunity drops in winter and following simple doctor-recommended habits, you can significantly reduce your risk of infections and stay healthy throughout the season.

At Malla Reddy Narayana Hospital, Hyderabad, our specialists are committed to helping individuals and families stay protected during winter. If you have frequent infections, persistent fatigue, or winter-related health concerns, book an appointment with our expert doctors today. Early care can keep you healthier all season long.