Clear Runny Nose Symptoms, Causes & Common Questions

A runny nose with clear discharge can be caused from a viral or bacterial infection, allergies, or in very rare cases, a sign of a severe brain injury. Fortunately, the most common cause of a runny nose like water is the common cold, or sinusitis. Read below for more information causes and treatment options.

Clear Runny Nose Symptoms

A runny nose with clear mucus is a common occurrence and is usually not serious. Clear discharge occurs most often when your nose is expelling irritants due to an allergy or an illness. A "runny nose" of any kind is also called rhinorrhea. However, in rare cases, this clear nasal discharge can be a sign of cerebrospinal fluid (CSF) leaking through a break in the lining of the brain — which is an emergency.

Common characteristics of a clear runny nose

The following characteristics will likely present with a viral infection or an allergy.

  • Clear, watery discharge that leaking out of both nostrils
  • Low-grade fever: This is a fever of 100 degrees Fahrenheit or less, or there may be no fever at all.
  • Sudden-onset: Symptoms may begin within a day.
  • Nasal congestion
  • Coughing
  • Watery eyes
  • Sneezing
  • An itchy feeling in your nose, throat, and eyes

Symptoms of a foreign body in the nose

Symptoms may differ slightly if a foreign object is in the nose.

  • Clear, watery discharge leaking out of one nostril
  • Traces of blood: These traces will come out of the same nostril as the discharge.
  • A foul odor coming out of the nose
  • A whistling sound as air passes through the nose

Symptoms of a cerebrospinal fluid leak

The following symptoms are likely with a CSF leak.

Duration of symptoms

You can expect a clear runny nose to last a certain amount of time depending on the cause.

  • A common cold: A cold will likely last for about 10 to 14 days.
  • Allergies: Allergies last as long as the allergen is around.
  • CSF leak: See a physician to treat a cerebrospinal fluid leak right away.

Who is most often affected?

The following people are more likely to experience a clear runny nose.

  • Anyone who has a common cold or seasonal allergies: You are likely to have a clear runny nose at some point.
  • Anyone with a head injury or other impact to the brain: A traumatic CSF leak can happen to anyone who has had a head injury, an epidural steroid injection for pain management, or brain surgery.
  • If you are over 30 or have certain conditions: 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?

Again, a clear runny nose is rarely severe; however, the severity will depend on the cause.

  • Not serious: A clear nasal discharge due to the common cold or an allergy is rarely severe.
  • Moderately serious: If there are symptoms of influenza along with the clear discharge, you may need to see a physician for supportive care.
  • Serious: If there are symptoms of cerebrospinal fluid leak, this is a medical emergency and you must get immediate treatment.

Clear Runny Nose Causes

The following details may help you better understand your symptoms and if and when you need to see a physician.

Infectious causes

Infectious causes of a clear, runny nose may include the following.

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


An allergic reaction to an inhaled substance, such as pollen or dust, will cause 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 — as a curious child may do so intentionally. Something may become lodged in your nose on accident. A nasal spray may run back out if you do not allow it to drain into the back of your nose and sinuses.

Rare and unusual causes

Less common causes of a clear, runny nose include the following.

  • Cerebrospinal fluid leak with trauma: 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. Cerebrospinal fluid can then 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.
  • CSF leaks without trauma: It's possible to have a CSF leak even when there has been no trauma. Spontaneous CSF leaks are due to 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 and they are considered rare.

6 Conditions of Clear Runny Nose

This list does not constitute medical advice and may not accurately represent what you have.

Common cold

The common cold is a viral infection of the upper respiratory tract, which includes the nose, mouth, sinuses, throat, and larynx. There are over 200 viruses that can cause upper respiratory infections, and usually the exact virus behind a cold is never known.

The common cold is, of course, very common...

Acute viral sinusitis

Acute viral sinusitis, also called viral rhinosinusitis or "sinus infection," occurs when viruses take hold and multiply in the sinus cavities of the face.

It is most often caused by the same viruses that cause the common cold and spreads the same way, through an infected person's coughing or sneezing.

Because children have small, underdeveloped sinuses, this illness is far more common in adults.

Symptoms include clear nasal discharge (not greenish or yellowish,) fever, and pain if facial sinuses are pressed.

If there is rash, severe fatigue, or neurologic symptoms (seizures, loss of sensation, weakness, or partial paralysis,) see a medical provider to rule out more serious conditions.

Diagnosis can usually be made through history and examination alone.

Antibiotics only work against bacteria and cannot help against a viral illness. Therefore, treatment consists of rest, fluids, and fever/pain reducers such as ibuprofen. (Do not give aspirin to children.) Symptoms of viral sinusitis last for about seven to ten days. As with the common cold, the best prevention is frequent and thorough handwashing.

Rarity: Common

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

Urgency: Self-treatment

New-onset seasonal allergies

New-onset seasonal allergies, also called adult-onset seasonal allergies, are sensitivities to pollen, mold, and other irritants that cause nasal congestion, runny nose, sneezing, itchy eyes, and sore throat.

Seasonal allergies commonly begin in childhood but can start at any age, especially among those with a family history. Moving to a different geographic location may trigger the allergy in someone with a genetic predisposition. Anyone with asthma is more likely to experience adult-onset seasonal allergies.

Sometimes the symptoms are actually from "pregnancy rhinitis" – nasal congestion and sneezing due to the effects of pregnancy hormones on the nasal tissue.

A new-onset allergy is often thought to be a cold, but a cold will clear up without treatment. Allergies persist, never getting better or worse, and can interfere with quality of life.

Diagnosis is made by an allergist, who will use skin tests and blood tests.

There is no cure for seasonal allergies but the symptoms can be managed for greater comfort and relief. Antihistamines, corticosteroid nasal sprays, and immunotherapy or "allergy shots" can be very effective.

Rarity: Common

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

Urgency: Self-treatment

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.

Rarity: Common

Top Symptoms: fatigue, irritability, trouble sleeping, runny nose, congestion

Symptoms that never occur with chronic allergies: fever, yellow-green runny nose, chills, muscle aches

Urgency: Self-treatment

Non-allergic rhinitis

Rhinitis simply means "inflammation of the nose." When it is caused by something other than allergies, it is called vasomotor rhinitis. "Vasomotor" simply refers to the constriction or dilation of blood vessels.

Different substances can trigger the vasomotor reaction, even though it is not an allergic reaction. Common causes are certain medications; air pollution; and chronic medical conditions.

Symptoms include runny nose, sneezing, congestion, and postnasal drip. Since no allergy is involved, there will not be the scratchy throat or itchy eyes and nose of allergic rhinitis.

A medical provider should be seen for ongoing symptoms, since they can interfere with quality of life. Also, using over-the-counter medications meant for allergic rhinitis will not help in a case of vasomotor rhinitis.

Diagnosis is made through patient history, physical examination, and allergy tests, in order to rule out allergies as a cause of the symptoms.

Treatment involves using the appropriate medications to ease the symptoms, and avoiding any triggers as much as possible.

Rarity: Common

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

Urgency: Self-treatment

Chronic sinusitis

Chronic sinusitis is also called chronic rhinosinusitis. It is an inflammation of the sinuses, or open spaces of the skull, above and below the eyes. "Chronic," in this case, means the condition has persisted for weeks in spite of treatment and has probably followed several cases of acute sinusitis.

The condition may start with a viral, bacterial, or fungal upper respiratory tract infection; asthma; allergies; or nasal polyps.

Symptoms include facial pain, swelling, and nasal congestion. There is often fatigue; greenish or yellowish nasal discharge; loss of sense of smell; ear pain; cough; and sore throat.

Chronic sinusitis should be seen by a medical provider, especially if symptoms worsen. The condition interferes with quality of life and the ongoing infection can become serious.

Diagnosis is made through patient history; physical examination; sinus cultures; skin tests for allergies; CT scan of the head; and nasal endoscopy (rhinoscopy.)

Treatment may involve saline nasal irrigation; nasal spray corticosteroids; oral corticosteroids; antibiotics for bacterial infection; immunotherapy for allergies; and, in some cases, surgery to remove polyps or other obstructions.

Rarity: Common

Top Symptoms: fatigue, headache, trouble sleeping, congestion, runny nose

Symptoms that always occur with chronic sinusitis: chronic sinusitis symptoms

Urgency: Primary care doctor

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Clear Runny Nose Treatments and Relief

At-home treatments

You can try the following clear runny nose remedies at home.

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

When to see a doctor

You should schedule an appointment for the following.

  • Nasal drainage that becomes thick, yellow to green, or foul-smelling: See a physician if you also have a headache, sore throat, or fever.
  • Ear pain, sinus pain, sore throat, or persistent cough: If you also have clear mucus discharge from your nose, your mucus may be too thick to drain and cause irritation and further infection.

When it is an emergency

Seek immediate clear runny nose treatment in the emergency room or call 911 if you have a severe headache with clear drainage from one nostril, especially if this follows a head injury, surgery to your head, or epidural steroid injection. The drainage may or may not show signs of blood.


Not all causes of a clear runny nose are preventable. However, there are some measures you can take to keep yourself in good health.

  • Wash your hands frequently: This is especially important before preparing meals.
  • Avoid touching your nose, eyes, or face: If you must, make sure to wash your hands before and after touching your face to limit the spread of germs.
  • Find an allergy medicine that works for you: If you suffer from seasonal allergies, there may be an effective over-the-counter option available or you can consult your physician.
  • Get plenty of sleep: You should get 7-9 hours of sleep each night. Try to get up and go to bed at the same time each day.
  • Eat a balanced diet to ensure proper nutrition: Make sure to eat plenty of fruits and vegetables, lean meats and other proteins, healthy fats, and whole grains.
Hear what 1 others are saying
Clear fluid running nosePosted April 24, 2020 by P.

I'm usually ok during the night. Once I go down stairs to let the dogs out I'm still ok. As soon as I drink or eat something, within about 15-20 sec. later, my nose starts to run like a faucet. About 1/2 hour if I don't have anything to drink or eat I'm OK. Forget it at dinner time, I have to have a box of tissues with me. If I just have a drink of water when I'm thirsty or take my meds, I am OK. I'm constantly being told by my wife and daughters, "Your nose is running." At times you don't realize it, since the fluid is warm, until it cools off. Then you realize it.

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