Read below about clear runny nose, including causes, treatment options and remedies. Or get a personalized analysis of your clear runny nose from our A.I. health assistant. At Buoy, we build tools that help you know what’s wrong right now and how to get the right care.

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Clear Runny Nose Symptoms

A runny nose with clear mucus is a very common symptom and usually is not serious. The clear discharge occurs most often when the nose is trying to expel irritating substances due to an allergy or an illness — it's actually a normal process. However, in rare cases, this clear nasal discharge can be a sign of a cerebrospinal fluid (CSF) leak through a break in the lining of the brain. This would constitute a medical emergency. A "runny nose" of any kind is also called rhinorrhea.

With a viral infection or an allergy:

  • Clear, watery discharge that is usually from both nostrils.
  • There may be a low-grade fever (100 degrees Fahrenheit or less) or no fever at all.
  • May start rather abruptly, within one day.
  • Nasal congestion.
  • Coughing.
  • Watery eyes.
  • Sneezing.
  • Itching in nose, throat, and eyes.

With a foreign body in the nose:

  • Clear, watery discharge only from one nostril.
  • Traces of blood from the same nostril as the discharge.
  • A foul odor from the nose.
  • A whistling sound as breath passes through the nose.

With a cerebrospinal fluid leak:

  • Clear, watery discharge that is often from one nostril only.
  • Metallic or salty taste in the mouth.
  • Reduced sense of smell.
  • Ringing in the ears.
  • Postural headache, a headache that comes and goes depending on whether the person is sitting up, lying down, etc.

Clear runny nose symptom duration:

  • A common cold will last for about 10 to 14 days.
  • Allergies last as long as the allergen is present.
  • A cerebrospinal fluid leak must be treated right away.

Who is most often affected by clear runny nose symptoms?

  • Anyone who suffers from a common cold or from seasonal allergies is quite likely to have a clear runny nose at some point.
  • A traumatic CSF leak can happen to anyone who has had a head injury, an epidural steroid injection for pain management, or brain surgery.
  • A spontaneous CSF leak most often occurs in someone over the age of 30 who also has a malformation of the skull, recurrent episodes of meningitis, or a brain tumor.

Are clear runny nose symptoms serious?

  • A clear nasal discharge due to the common cold or an allergy is rarely ever serious.
  • If there are symptoms of influenza along with the clear discharge, the person may need to see a medical provider for supportive care.
  • If there are symptoms of cerebrospinal fluid leak, that is a medical emergency and the person must have immediate emergency care.

Clear Runny Nose Causes Overview

Many conditions can cause a clear runny nose as a symptom. We've listed several different causes here, in approximate order from most to least common:


  • Viral infections are the most common cause of a clear runny nose.
  • Bacterial infections can also cause the clear discharge, but it will often turn to yellow or green after a few days.


  • An allergic reaction to any sort of inhaled substance, such as pollen or dust, will cause a clear nasal discharge as the body tries to clear the substance out.
  • An allergy will also cause irritated, itchy eyes and throat along with the clear runny nose but does not cause fever or a headache.

Foreign body or substance:

  • A small object may be pushed into the nostril. Children will sometimes do this.
  • Nasal spray may run back out if the person sits up too soon after using it.

Rare and unusual cause types:

  • In cases of severe head injury – even in a closed head injury, meaning there is no visible external wound – there can be a tear in the covering of the brain that allows cerebrospinal fluid to leak into the sinuses and out through the nose.

  • Brain, head, or neck surgery, or epidural steroid injection, can also result in a CSF leak.

  • It's possible to have a CSF leak even when there has been no trauma. Spontaneous CSF leak is caused by a fistula – an abnormal opening –between the lining of the brain and the base of the skull. The reason for this formation is not entirely known.

A.I. Health Assistant Causes for Clear Runny Nose

The list below shows results from the use of our A.I. Health Assistant by Buoy users who experienced clear runny nose. This list does not constitute medical advice.

  1. 1.Common Cold

    The common cold is a viral infection of the upper respiratory tract.

    The common cold resolves within 7 to 10 days.

    Top Symptoms:
    fatigue, headache, cough, sore throat, congestion
    Symptoms that never occur with common cold:
    being severely ill, severe muscle aches, rash, severe headache, sinus pain
  2. 2.Acute Viral Sinusitis

    Sinusitis is an inflammation of the sinus spaces behind the nose and cheeks. These spaces produce mucus, which drains into the nose. If the nose is swollen or if the mucus does not drain, this can block the sinuses and cause pain or infection.

    Symptoms should subside within 7-10 days

    Top Symptoms:
    headache, cough, sinusitis symptoms, sore throat, congestion
    Symptoms that always occur with acute viral sinusitis:
    sinusitis symptoms
    Symptoms that never occur with acute viral sinusitis:
    being severely ill
  3. 3.New - Onset Seasonal Allergies

    Allergic rhinitis, is an overreaction by the immune system to allergens in the air. While pollen often causes allergies, other culprits include dust, animal dander, and mold.

    Allergies are often seasonal.

    Top Symptoms:
    sore throat, congestion, cough with dry or watery sputum, mucous dripping in the back of the throat, fatigue
    Symptoms that never occur with new-onset seasonal allergies:
    fever, yellow-green runny nose, chills, muscle aches

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  4. 4.Chronic Allergies

    Allergies are an overreaction by the immune system to something that does not bother most other people. Many people who have allergies are sensitive to pollen, but other things such as dust mites, animal dander, cockroaches, and mold can also cause a reaction.


    Top Symptoms:
    fatigue, irritability, trouble sleeping, runny nose, congestion
    Symptoms that never occur with chronic allergies:
    fever, yellow-green runny nose, chills, muscle aches
  5. 5.Non - Allergic Rhinitis

    Nonallergic rhinitis is a medical condition which involves chronic (persistent) sneezing and having a runny, congested nose without any apparent cause. While the symptoms of nonallergic rhinitis are similar to those of allergic rhinitis (hay fever), there is no allergic reaction. Nonallergic rhinitis can be triggered by certain odors, weather changes, medications, or foods.

    Long-term condition but may go away without treatment.

    Top Symptoms:
    congestion, mucous dripping in the back of the throat, runny nose, frequent sneezing, eye itch
    Symptoms that never occur with non-allergic rhinitis:
    fever, sinus pain, facial fullness or pressure
  6. 6.Chronic Sinusitis

    Chronic sinusitis is an inflammation of the sinuses (hollow cavities behind the nose & cheeks) that lasts more than 12 weeks and can continue for months or years.

    Longer than 3 months.

    Top Symptoms:
    fatigue, headache, trouble sleeping, congestion, runny nose
    Symptoms that always occur with chronic sinusitis:
    chronic sinusitis symptoms
    Primary care doctor

Clear Runny Nose Treatments and Relief

Seek immediate clear runny nose treatment in the emergency room or call 911 if:

  • The person has a severe headache with clear drainage from one nostril, especially if this follows a head injury, head surgery, or epidural steroid injection. The drainage may or may not show signs of blood.

Schedule an appointment for:

  • Nasal drainage that becomes thick, yellow to green, and/or foul smelling, especially if there are other symptoms such as headache, sore throat, or fever.
  • Ear pain, sinus pain, sore throat, and/or persistent cough along with clear mucus discharge from the nose. The mucus may be too thick to drain properly and causing irritation, which can lead to further infection.

Clear runny nose remedies that you can try at home:

  • Drink extra fluids.
  • Use a humidifier. This will help keep the mucus thin rather than thick and sticky, so that it can drain out and help take the illness-causing agents with it.
  • Use saline nasal sprays for soothing moisture, which may provide a little extra comfort.
  • Over-the-counter antihistamines may be helpful for allergies, though some can cause drowsiness.

Questions Your Doctor May Ask About Clear Runny Nose

  • Q.Do you have a stuffy nose?
  • Q.Any fever today or during the last week?
  • Q.Do you have a cough?
  • Q.Are you experiencing a headache?

If you've answered yes to one or more of these questions, try our clear runny nose symptom checker to find out more.

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Clear Runny Nose Symptom Checker Statistics

  • People who have experienced clear runny nose have also experienced:

    • 11% Cough
    • 6% Sore Throat
    • 6% Frequent Sneezing
  • People who have experienced clear runny nose had symptoms persist for:

    • 46% Less Than a Week
    • 21% Less Than a Day
    • 12% One to Two Weeks
  • People who have experienced clear runny nose were most often matched with:

    • 33% Common Cold
    • 33% Acute Viral Sinusitis
    • 33% New - Onset Seasonal Allergies
  • Source: Aggregated and anonymized results from visits to the Buoy AI health assistant (check it out by clicking on “Take Quiz”).

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