Runny nose
A runny nose may be clear, thick or accompanied by mucus draining into the throat. Duration and associated symptoms matter more than colour alone.
What to know first
Nasal discharge, sneezing, congestion or postnasal drip.
When to see a clinician
Seek advice if symptoms persist, worsen after improving or interfere with sleep.
Possible causes
Common causes include a cold, allergic rhinitis, non-allergic rhinitis and sinusitis. A foreign body should be considered in a child with foul-smelling discharge from one nostril.
Examination and tests
We examine the nose and consider the timing, triggers, fever and facial pain. Tests are chosen when needed to clarify the cause.
Tests are selected according to your symptoms and examination. Specialist tests or procedures may require referral.
Treatment
Nasal treatment, oral medicines or sprays are selected for the cause. Antibiotics are used only when indicated.
These are general treatment options. Your clinician will discuss which approach fits your condition; not every treatment described is provided at this clinic.
What you can do at home
Blow the nose gently, maintain fluids and avoid inserting objects. Note seasonal or environmental triggers.
Frequently asked questions
Can the colour identify the cause?
No. Colour alone is not enough to diagnose an infection or choose an antibiotic.
What should I tell the clinician?
Tell us when symptoms began, whether they are changing, your medicines and allergies, and any relevant medical conditions. For a child, describe changes in feeding, sleep or response to sound.
Related symptoms and conditions
Air quality and respiratory symptoms
If symptoms are triggered by cold air or indoor dryness, see our guide to air conditioning and nose/throat symptoms. Air conditioning, rhinitis and throat discomfort ›
Visiting Honda ENT Clinic
Check temporary changes
| Day | Morning | Afternoon |
|---|---|---|
| Mon / Tue / Wed / Fri | 9:00–12:30 | 15:00–18:20 |
| Saturday | 9:00–11:00 | 14:00–16:00 |
| Closed | Thursday, Sunday and public holidays | |
Reception opens 15 minutes before each session. Walk-ins are welcome for general consultations. Vaccinations may require an appointment.
Please call before visiting if you have a fever of 37.5°C or higher, a recent positive infection test, a household member with an infection, or would like infection testing. The waiting-time service is in Japanese.
Schedules can change. Check clinic news or call before travelling.
About this information and references
This information is published by Honda ENT Clinic and is intended as general guidance. Individual diagnosis and treatment require a clinical assessment. Updated: 25 October 2026.
About Medical Director Dr. Yusuke Honda