Coryza: What It Means and What Causes It

What coryza means

The word comes from the Greek koryza, meaning "running at the nose". In medicine it means acute inflammation of the mucous membrane that lines the nose, which is why it is also called acute rhinitis. The swollen lining makes extra mucus, so the nose runs. The swelling also narrows the airway, so the nose feels blocked.

You will mostly see the word in medical notes, vaccine leaflets and old textbooks. A doctor who writes "coryzal" or "coryzal symptoms" means the symptoms of a cold. A doctor who writes "a coryzal child" means a child with a cold. It describes what is happening, not the cause, so coryza is a symptom rather than a diagnosis.

Coryzal symptoms: what to expect

Coryza from a cold follows a predictable pattern:

1. Days 1 to 2: a scratchy or sore throat, sneezing and a clear, watery runny nose. You may feel tired and slightly feverish.
2. Days 2 to 4: the nose gets more congested. Mucus thickens and may turn white, yellow or green as immune cells collect in it. This is when you are most contagious.
3. Days 4 to 7: the blockage eases. Mucus that drips down the back of the throat (post-nasal drip) often causes a cough, especially at night.
4. Days 7 to 10: most symptoms have gone. A dry cough can last another week or two.

Other symptoms that often come with coryza:

• Sneezing and an itchy or tickly nose
• Watery eyes
• A reduced sense of smell and taste
• A mild headache or pressure across the cheeks and forehead
• Mild body aches and a low-grade fever, more common in children

What causes coryza

Viral infections (most cases)

More than 200 viruses can cause a cold. Rhinoviruses cause up to half of all colds. Seasonal coronaviruses, adenoviruses, RSV and parainfluenza viruses cause most of the rest. They spread through droplets from coughs and sneezes and from hands that touch the eyes or nose after touching contaminated surfaces. Adults get 2 to 4 colds a year. Young children get 6 to 8, so a preschool child can have coryza for weeks at a time over the winter.

Flu and COVID-19

Influenza and COVID-19 can both start with coryza. The difference is usually how quickly and how badly you feel ill. Flu typically hits suddenly with a high fever, chills, strong muscle aches and exhaustion. A cold builds up gradually and stays mostly in the nose and throat. A home test helps to tell COVID-19 apart.

Measles

Coryza is one of the classic early signs of measles, along with cough and conjunctivitis (red, watery eyes): the "three Cs". A high fever comes before the rash, which starts on the face 3 to 5 days later. If someone who is not vaccinated has coryza with a high fever and sore red eyes, phone a doctor before visiting, because measles is highly contagious.

Allergies (allergic coryza)

Pollen, dust mites, mold or animal dander can trigger the same runny, sneezy nose without any infection. This is hay fever, or allergic rhinitis. It points to allergy rather than a cold when:

• the itching, especially of the eyes and roof of the mouth, is intense
• the discharge stays clear and watery
• there is no fever or sore throat
• symptoms last for weeks or come back in the same season or setting every time

Non-allergic triggers

The nose can also run in response to cold air (skier's nose), spicy food (gustatory rhinitis), strong smells, smoke and hormonal changes in pregnancy. Overusing decongestant nasal sprays for more than a few days can cause rebound congestion. This is called rhinitis medicamentosa.

Less common causes

• Sinusitis: a cold that lasts more than 10 days, or gets worse after starting to improve, may have turned into acute sinusitis.
• A foreign object in the nose: in a young child, a smelly discharge from one nostril suggests something may be stuck there.
• Cerebrospinal fluid leak: this is rare. A constant, watery drip from one side, especially after a head injury or surgery, needs medical assessment.

Coryza vs a common cold, flu and hay fever

How coryza is diagnosed

Coryza is diagnosed from your symptoms. A doctor or pharmacist will ask how quickly it started, whether you have a fever, and whether it happens at certain times of year or in certain places. Tests are rarely needed. A rapid flu or COVID-19 test may be offered when the result would change treatment, for example in someone pregnant, older or with a weak immune system. Allergy skin-prick or blood tests can confirm allergic rhinitis if symptoms keep coming back.

How to treat coryza

There is no cure for a viral cold. Your immune system clears it. Treatment eases the symptoms while that happens.

Things that help at home

• Saline nasal spray or rinse: salt water thins mucus and clears the nose. It is safe at any age, including for babies with saline drops and gentle suction.
• Fluids and rest: warm drinks soothe the throat and loosen mucus.
• Steam or a humidifier: moist air can ease a blocked nose. Never use hot steam with young children because of the risk of burns.
• Honey: honey in a warm drink eases cough and throat irritation in adults and children over 1 year. Never give honey to babies under 12 months.
• Raise your head at night: this reduces post-nasal drip and night-time coughing.

Medicines you can buy

• Pain relievers such as acetaminophen (paracetamol) or ibuprofen for fever, aches and sore throat. Follow the label dose. Do not give aspirin to children or teenagers.
• Decongestant sprays such as oxymetazoline can unblock the nose quickly. Use them for no more than 3 days to avoid rebound congestion.
• Oral decongestants may help some adults. They are not suitable for people with high blood pressure, heart disease or glaucoma, or for young children.
• Antihistamines work well for allergic coryza. They do little for a cold apart from drying the nose a little.
• Cough and cold medicines are not recommended for children under 6 in the US or UK, because they carry risks and have no proven benefit at that age.

Antibiotics do not kill cold viruses. They will not shorten coryza, and they cause side effects and resistance. They are only used if a bacterial complication such as sinusitis, an ear infection or pneumonia develops and a clinician confirms it.

Treating allergic coryza

If allergy is the cause, the most effective treatments are avoiding the trigger, a steroid nasal spray used daily throughout the season, and non-drowsy antihistamines. Allergen immunotherapy can help people whose symptoms are severe and persist despite these treatments.

Preventing coryza

• Wash your hands often, and avoid touching your eyes and nose.
• Keep your distance from people with active cold symptoms during their first few days.
• Catch coughs and sneezes in a tissue or your elbow.
• Keep up to date with flu, COVID-19 and MMR (measles) vaccines. There is no vaccine for the common cold.
• Get enough sleep. People who sleep less than 6 hours are noticeably more likely to catch a cold after exposure.

Frequently asked questions

What is the medical definition of coryza?

Coryza is acute inflammation of the mucous membrane of the nose, which causes a runny nose, nasal blockage and sneezing. It is the medical term for a head cold or acute rhinitis.

What are coryzal symptoms?

"Coryzal symptoms" means the symptoms of a cold: runny or blocked nose, sneezing, sore throat, watery eyes and sometimes a mild cough and low fever. Doctors often use the phrase in notes and on vaccine and medicine leaflets.

Is coryza contagious?

When a virus causes it, yes. Cold viruses spread most easily in the first 2 to 3 days of symptoms and can spread for up to about 2 weeks. Allergic coryza and coryza from cold air or spicy food are not contagious.

How long does coryza last?

A cold-related runny nose usually clears within 7 to 10 days, though a cough can last 2 to 3 weeks. If nasal symptoms last longer than 10 days, or get worse after getting better, see a doctor to check for sinusitis.

Does green mucus mean I need antibiotics?

No. Mucus often turns yellow or green partway through an ordinary cold, because it contains white blood cells. Color alone does not mean a bacterial infection. Persistent symptoms, high fever or severe facial pain matter more.

Is coryza the same as rhinitis?

They overlap. Rhinitis is inflammation of the nasal lining from any cause, including allergies. Coryza usually refers to the acute, short-lived kind that comes with a cold.

Can coryza be a sign of measles?

Yes. Coryza, cough and conjunctivitis together with a high fever are the typical early signs of measles. The rash appears a few days later. Anyone who is unvaccinated and has these symptoms should phone a doctor before going in, so others are not exposed.