Dr. Ameen, ENT Specialist in Kuala Lumpur

Many patients say:
“Doctor, my left side is always blocked.”
Then a few hours later, it switches.

Do you know why that happens?

Because your nose has a built-in rhythm called the nasal cycle.

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What is the nasal cycle?

Inside the nose, soft tissue (turbinates) naturally swells and decongests in a cycle. One side becomes slightly more open while the other side becomes slightly less open. Then it alternates.

This is normal physiology. Most people don’t notice it until:

• They have allergies or rhinitis
• They lie down
• They get a cold
• The air is dry (AC exposure)

Your own rhinitis content already notes symptoms worsen at night and affect sleep—this ties perfectly into the nasal-cycle explanation.

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When it becomes NOT normal

See an ENT if the blockage is:

• Always on one side, consistently, for weeks
• Associated with recurrent nosebleeds
• Associated with facial swelling, severe pain, or reduced smell
• Getting progressively worse

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Common reasons people notice it more in Kuala Lumpur

• Allergic rhinitis (“resdung” symptoms)
• Air-conditioned environments (dry mucosa)
• Viral URTI
• Deviated septum (but many have it without symptoms)

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What helps

• Saline irrigation
• Treat rhinitis properly (not just repeated decongestant sprays)
• Sleep with head slightly elevated if congestion worsens supine

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Key takeaway

Feeling one nostril more blocked is often normal.
Feeling one nostril blocked all the time is not.

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FAQs

1. Is it normal if it alternates? Yes. That pattern strongly suggests nasal cycle.
2. Does it mean I have sinus? Not necessarily.
3. Will a deviated septum always cause blockage? No. Many people compensate well.
4. Can rhinitis make the cycle feel worse? Yes, swelling amplifies it.
5. When should I worry? Persistent one-sided blockage, bleeding, or worsening symptoms.

Article reviewed by Dr Ameen, ENT Specialist KL