Rhinorrhea (

American English American English, sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the United States. English is the Languages of the United States, most widely spoken lang ...

), also spelled rhinorrhoea or rhinorrhœa (

British English British English is the set of Variety (linguistics), varieties of the English language native to the United Kingdom, especially Great Britain. More narrowly, it can refer specifically to the English language in England, or, more broadly, to ...

), or informally runny nose is the free discharge of a thin

mucus Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both Serous fluid, serous and muc ...

fluid from the nose; it is an extremely common condition. It is a common

symptom Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. A sign for example may be a higher or lower temperature ...

allergies Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include Allergic rhinitis, hay fever, Food allergy, food al ...

(

hay fever Allergic rhinitis, of which the seasonal type is called hay fever, is a type of rhinitis, inflammation in the nose that occurs when the immune system overreacts to allergens in the air. It is classified as a Allergy, type I hypersensitivity re ...

) or certain viral infections, such as the

common cold The common cold, or the cold, is a virus, viral infectious disease of the upper respiratory tract that primarily affects the Respiratory epithelium, respiratory mucosa of the human nose, nose, throat, Paranasal sinuses, sinuses, and larynx. ...

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the coronavirus SARS-CoV-2. In January 2020, the disease spread worldwide, resulting in the COVID-19 pandemic. The symptoms of COVID‑19 can vary but often include fever ...

. Rhinorrhea varies in color and consistency depending upon the underlying cause. It can be a side effect of

crying Crying is the dropping of tears (or welling of tears in the eyes) in response to an emotional state or physical pain. Emotions that can lead to crying include sadness, anger, joy, and fear. Crying can also be caused by relief from a period ...

, exposure to cold temperatures,

cocaine Cocaine is a tropane alkaloid and central nervous system stimulant, derived primarily from the leaves of two South American coca plants, ''Erythroxylum coca'' and ''Erythroxylum novogranatense, E. novogranatense'', which are cultivated a ...

abuse, or

drug withdrawal A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug i ...

, such as from

methadone Methadone, sold under the brand names Dolophine and Methadose among others, is a synthetic opioid used medically to treat chronic pain and opioid use disorder. Prescribed for daily use, the medicine relieves cravings and opioid withdrawal sym ...

or other

opioid Opioids are a class of Drug, drugs that derive from, or mimic, natural substances found in the Papaver somniferum, opium poppy plant. Opioids work on opioid receptors in the brain and other organs to produce a variety of morphine-like effects, ...

s. Treatment for rhinorrhea may be aimed at reducing symptoms or treating underlying causes. Rhinorrhea usually resolves without intervention, but may require treatment by a doctor if symptoms last more than 10 days or if symptoms are the result of foreign bodies in the nose. The term rhinorrhea was coined in 1866 from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

''rhino-'' ("of the nose") and ''-rhoia'' ("discharge" or "flow").

Signs and symptoms

Rhinorrhea is characterized by an excess amount of mucus production in response to parasympathetic stimulation and inflammatory cytokines by

mucous membranes A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...

that line the nasal cavities. The membranes create mucus faster than it can be processed, causing a backup of mucus in the nasal cavities. As the cavity fills up, it blocks off the air passageway, causing difficulty breathing through the nose. Air caught in nasal cavities – namely the sinus cavities, cannot be released and the resulting pressure may cause a headache or facial pain. If the sinus passage remains blocked, there is a chance that

sinusitis Sinusitis, also known as rhinosinusitis, is an inflammation of the mucous membranes that line the sinuses resulting in symptoms that may include production of thick nasal mucus, nasal congestion, facial congestion, facial pain, facial pressure ...

may result. If the mucus backs up through the

Eustachian tube The Eustachian tube (), also called the auditory tube or pharyngotympanic tube, is a tube that links the nasopharynx to the middle ear, of which it is also a part. In adult humans, the Eustachian tube is approximately long and in diameter. It ...

, it may result in ear pain or an

ear infection Otitis is a general term for inflammation in ear or ear infection, inner ear infection, middle ear infection of the ear, in both humans and other animals. When infection is present, it may be viral or bacterial. When inflammation is present due t ...

. Excess mucus accumulating in the throat or back of the nose may cause a

post-nasal drip Post-nasal drip (PND), also known as upper airway cough syndrome (UACS), occurs when excessive mucus is produced by the nasal mucosa. The excess mucus accumulates in the back of the nose, and eventually in the throat once it drips down the back of ...

, resulting in a sore throat or coughing. Additional symptoms include lacrimation,

sneezing A sneeze (also known as sternutation) is a semi-autonomous, convulsive expulsion of air from the lungs through the nose and mouth, usually caused by foreign particles irritating the nasal mucosa. A sneeze expels air forcibly from the mouth a ...

nosebleeds A nosebleed, also known as epistaxis, is an instance of bleeding from the nose. Blood can flow down into the stomach, and cause nausea and vomiting. In more severe cases, blood may come out of both nostrils. Rarely, bleeding may be so significan ...

, and nasal discharge.

Causes

A runny nose can be caused by anything that irritates or inflames the nasal tissues, including infections such as the common cold, influenza, allergies and various irritants. Some people have a chronic runny nose for no apparent reason (non-allergic rhinitis or vasomotor rhinitis). Less common causes include polyps, a foreign body, a tumor or migraine-like headaches. Some causes of rhinorrhea include: acute sinusitis (nasal and sinus infection), allergies, chronic sinusitis, common cold, coronaviruses (COVID-19), decongestant nasal spray overuse, deviated septum, dry air,

eosinophilic granulomatosis with polyangiitis Eosinophilic granulomatosis with polyangiitis (EGPA), formerly known as allergic granulomatosis, is an extremely rare autoimmune condition that causes inflammation of small and medium-sized blood vessels (vasculitis) in persons with a history of ...

granulomatosis with polyangiitis Granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis (WG), after Nazi German physician Friedrich Wegener, is a rare, long-term, systemic disorder that involves the formation of granulomas and vasculitis, inflammatio ...

, hormonal changes, influenza (flu), lodged object, medicines (such as those used to treat high blood pressure, erectile dysfunction, depression, seizures and other conditions), nasal polyps, non-allergic rhinitis (chronic congestion or sneezing not related to allergies), occupational asthma, pregnancy, respiratory syncytial virus (RSV), spinal fluid leak, and tobacco smoke.

Cold temperatures

Rhinorrhea is especially common in cold weather. Cold-induced rhinorrhea occurs due to a combination of thermodynamics and the body's natural reactions to cold weather stimuli. One of the purposes of nasal mucus is to warm inhaled air to body temperature as it enters the body; this requires the nasal cavities to be constantly coated with liquid mucus. In cold weather the mucus lining nasal passages tends to dry out, so that mucous membranes must work harder, producing more mucus to keep the cavity lined. As a result, the nasal cavity can fill up with mucus. At the same time, when air is exhaled, water vapor in breath condenses as the warm air meets the colder outside temperature near the nostrils. This causes excess water to build up inside nasal cavities, spilling out through the nostrils.

Inflammatory

Infection

Rhinorrhea can be a symptom of other diseases, such as the

influenza Influenza, commonly known as the flu, is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These sympto ...

. During these infections, the nasal mucous membranes produce excess mucus, filling the nasal cavities. This is to prevent infection from spreading to the lungs and respiratory tract, where it could cause far worse damage. It has also been suggested that viral rhinorrhea is a result of viral evolution whereby virus variants that increase nasal secretion and are thus more resistant to the body's immune defenses are selected for. Rhinorrhea caused by these infections usually occur on

circadian rhythm A circadian rhythm (), or circadian cycle, is a natural oscillation that repeats roughly every 24 hours. Circadian rhythms can refer to any process that originates within an organism (i.e., Endogeny (biology), endogenous) and responds to the env ...

s. Over the course of a viral infection,

(the inflammation of the nasal tissue) may occur, causing the mucous membranes to release more mucus. Acute sinusitis consists of the nasal passages swelling during a viral infection. Chronic sinusitis occurs when sinusitis continues for longer than three months.

Allergies

Rhinorrhea can also occur when individuals with allergies to certain substances, such as

pollen Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...

, dust, latex, soy, shellfish, or animal dander, are exposed to these allergens. In people with sensitized immune systems, the inhalation of one of these substances triggers the production of the

antibody An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as pathogenic bacteria, bacteria and viruses, includin ...

immunoglobulin E Immunoglobulin E (IgE) is a type of antibody (or immunoglobulin (Ig) " isoform") that has been found only in mammals. IgE is synthesised by plasma cells. Monomers of IgE consist of two heavy chains (ε chain) and two light chains, with the ε ...

(IgE), which binds to

mast cell A mast cell (also known as a mastocyte or a labrocyte) is a resident cell of connective tissue that contains many granules rich in histamine and heparin. Specifically, it is a type of granulocyte derived from the myeloid stem cell that is a p ...

s and

basophil Basophils are a type of white blood cell White blood cells (scientific name leukocytes), also called immune cells or immunocytes, are cells of the immune system that are involved in protecting the body against both infectious disease and f ...

s. IgE bound to mast cells are stimulated by pollen and dust, causing the release of inflammatory mediators such as

histamine Histamine is an organic nitrogenous compound involved in local immune responses communication, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Discovered in 19 ...

. Histamine dilates blood vessels in the nose that increases vascular permeability to fluid and cause fluid leakage leading to rhinorrhea. In the nasal cavities, these inflammatory mediators cause inflammation and swelling of the tissue, as well as increased mucous production. Particulate matter in polluted air and chemicals such as chlorine and detergents, which can normally be tolerated, can make the condition considerably worse.

Crying

Rhinorrhea is also associated with shedding tears (lacrimation), whether from emotional events or from eye irritation. When excess

tears Tears are a clear liquid secreted by the lacrimal glands (tear gland) found in the eyes of all land mammals. Tears are made up of water, electrolytes, proteins, lipids, and mucins that form layers on the surface of eyes. The different types of ...

are produced, the liquid drains through the inner corner of the eyelids, through the

nasolacrimal duct The nasolacrimal duct (also called the tear duct) carries tears from the lacrimal sac of the eye into the nasal cavity. The duct begins in the eye socket between the maxillary and lacrimal bones, from where it passes downwards and backwards. ...

, and into the nasal cavities. As more tears are shed, more liquid flows into the nasal cavities, both stimulating mucus production and hydrating any dry mucus already present in the nasal cavity. The buildup of fluid is usually resolved via mucus expulsion through the nostrils.

Non-inflammatory

Head trauma

Rhinorrhea can be caused by a head injury, a serious condition. A

basilar skull fracture A basilar skull fracture is a bone fracture, break of a bone in the base of skull, base of the skull. Symptoms may include Battle sign, bruising behind the ears, periorbital ecchymosis, bruising around the eyes, or hemotympanum, blood behind the ...

can result in a rupture of the barrier between the sinonasal cavity and the

anterior cranial fossa The anterior cranial fossa is a depression in the floor of the cranial base which houses the projecting frontal lobes of the brain. It is formed by the orbital plates of the frontal, the cribriform plate of the ethmoid, and the small wings and ...

e or the

middle cranial fossa The middle cranial fossa is formed by the sphenoid bones, and the temporal bones. It lodges the temporal lobes, and the pituitary gland. It is deeper than the anterior cranial fossa, is narrow medially and widens laterally to the sides of the skull ...

e. This can cause the nasal cavity to fill with cerebrospinal fluid (

cerebrospinal fluid rhinorrhoea Cerebrospinal fluid rhinorrhoea (CSF rhinorrhoea) refers to the drainage of cerebrospinal fluid through the Human nose, nose (Rhinorrhea, rhinorrhoea). It is typically caused by a basilar skull fracture, which presents complications such as infect ...

, CSF rhinorrhea), a condition that can lead to a number of serious complications, including death if not addressed properly.

Other causes

Rhinorrhea can occur as a symptom of opioid withdrawal accompanied by

lacrimation Tears are a clear liquid secreted by the lacrimal glands (tear gland) found in the eyes of all land mammals. Tears are made up of water, electrolytes, proteins, lipids, and mucins that form layers on the surface of eyes. The different types of ...

. Other causes include

cystic fibrosis Cystic fibrosis (CF) is a genetic disorder inherited in an autosomal recessive manner that impairs the normal clearance of Sputum, mucus from the lungs, which facilitates the colonization and infection of the lungs by bacteria, notably ''Staphy ...

whooping cough Whooping cough ( or ), also known as pertussis or the 100-day cough, is a highly contagious, Vaccine-preventable diseases, vaccine-preventable Pathogenic bacteria, bacterial disease. Initial symptoms are usually similar to those of the common c ...

, nasal tumors, hormonal changes, and

cluster headaches Cluster headache is a neurological disorder characterized by recurrent severe headaches on one side of the head, typically around the eye(s). There is often accompanying eye watering, nasal congestion, or swelling around the eye on the affecte ...

. Rhinorrhea can also be the side effect of several genetic disorders, such as

primary ciliary dyskinesia Primary ciliary dyskinesia (PCD) is a rare, autosomal recessive genetic ciliopathy, that causes defects in the action of cilia lining the upper and lower respiratory tract, sinuses, Eustachian tube, middle ear, fallopian tube, and flagella of spe ...

, as well as common irritants such as spicy foods, nail polish remover, or paint fumes.

Treatment

In most cases, treatment for rhinorrhea is not necessary since it will clear up on its own, especially if it is the symptom of an infection. Generally, home remedies are used to treat rhinorrhea including maintaining hydration, hot shower steam,

nose-blowing Nose-blowing is the act of expelling nasal mucus by exhaling forcefully through the nose. This is usually done into a facial tissue or handkerchief, facial tissues being more hygienic as they are disposed of after each use while handkerchiefs are ...

or postural drainage. Although, blowing may be a quick-fix solution, it increases mucosal production in the sinuses, leading to frequent and higher mucus buildups in the nose in the medium term. Alternatively, saline or

vasoconstrictor Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vesse ...

nasal spray Nasal sprays are used to deliver medications Route of administration#Local, locally in the nasal cavities or systemic administration, systemically. They are used locally for conditions such as nasal congestion and allergic rhinitis. In some sit ...

s including expectorants and decongestants can be used, but may shrink or dry up nasal passages and become counterproductive after several days of use, causing

rhinitis medicamentosa Rhinitis medicamentosa (or RM, also known as rebound congestion) is a condition of rebound nasal congestion suspected to be brought on by extended use of topical decongestants (e.g., oxymetazoline, phenylephrine, xylometazoline, and naphazoli ...

. There are medicinal therapies available for allergic and infectious cases of rhinorrhea. Several types of

antihistamine Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides ...

s can be obtained relatively cheap to treat cases caused by allergies; antibiotics may help in cases of bacterial sinus infections.

References

External links

Coping with colds and flu
(NHS Direct) {{Respiratory pathology Symptoms and signs: Respiratory system Nose disorders