Non-allergic rhinitis happens when the lining of the inside of the nose becomes swollen and inflamed, usually because of swollen blood vessels and fluid building up in the tissues of the nose.

This swelling blocks the nasal passages and stimulates the mucus glands in the nose, resulting in the typical symptoms of a blocked or runny nose.

Some of the main causes of non-allergic rhinitis include:

• infection
• environmental triggers
• medicines and recreational drugs
• overuse of nasal decongestants
• hormone imbalance
• nasal tissue damage

Infection

In many cases, rhinitis develops as the result of an infection attacking the lining of the nose and throat.

This is usually a viral infection, such as a cold, but bacterial or fungal infections can occasionally cause rhinitis.

Environmental triggers

In some people, rhinitis develops as a result of environmental triggers, such as:

• smoke
• perfume
• paint fumes
• changes in the weather, such as a drop in temperature
• alcohol
• spicy food
• stress

The exact cause of this type of rhinitis is unknown, but it's most likely to happen in people with very sensitive nasal blood vessels.

Medications and drugs

Rhinitis can sometimes happen as a result of using certain medicines, including:

• angiotensin-converting enzyme (ACE) inhibitors – for high blood pressure
• beta-blockers – for various heart conditions
• non-steroidal anti-inflammatory drugs (NSAIDs) – to relieve pain
• nasal decongestant sprays

Rhinitis can also happen as a result of drug misuse (such as snorting cocaine).

Overuse of nasal decongestants

Nasal decongestant sprays work by reducing the swelling of the blood vessels in your nose.

However, if they're used for longer than 5 to 7 days at a time, they can cause the lining of your nose to swell up again. This can happen even after the cold or allergy that originally caused the problem has passed.

If you use more decongestants in an attempt to reduce the swelling, it's likely to make the problem worse.

Hormonal imbalance

Hormones may play a role in the enlargement of the nasal blood vessels that can lead to rhinitis.

Non-allergic rhinitis can also be caused by hormonal changes due to:

• pregnancy
• puberty
• taking hormone medication – such as HRT or the contraceptive pill

Various health conditions that cause a hormone imbalance in the body, such as an underactive thyroid gland (hypothyroidism), can also cause rhinitis.

Nasal tissue damage

Inside your nose, there are 3 ridges of bone covered by a layer of tissue. These layers of tissue are called turbinates. A type of rhinitis called atrophic rhinitis can occur if the turbinates become damaged.

Most cases of atrophic rhinitis happen when the turbinates are damaged or removed during surgery (sometimes it's necessary to surgically remove turbinates if they're obstructing your airflow). 

Turbinates play an important role in the functioning of your nose, such as keeping the inside of your nose moist and protecting the body from being infected with bacteria. If they're damaged or removed, the remaining tissue can become inflamed, crusty and prone to infection.

See your GP if you have symptoms of non-allergic rhinitis and it's affecting your quality of life.

Your GP will first ask about your symptoms. Certain symptoms, such as a cough or muscular aches and pains, would suggest that your rhinitis is caused by a viral infection.

Your GP may also ask about your medical history, as rhinitis can sometimes happen as a side effect of certain medicines.

Allergy tests

If your symptoms and medical history do not suggest an obvious cause, you may need to have further tests to check if your symptoms could be caused by an allergy. This is because the symptoms of allergic rhinitis can be very similar to those of non-allergic rhinitis.

Your GP may carry out a blood test to check if you have an allergy, or they may refer you to a hospital allergy clinic for more specific tests.

One of the main tests you may have at an allergy clinic is a "skin prick test". This is where your skin is pricked with a tiny amount of a suspected allergen to see if it reacts by becoming red, raised and itchy.

If the test results suggest you do not have an allergy, you may be diagnosed with non-allergic rhinitis.

Read more about allergy tests.

Further tests

In some cases, it may be necessary to have further tests in hospital to help diagnose non-allergic rhinitis and check for any complications, such as nasal polyps or sinusitis.

Specifically, examination with an endoscope is usually necessary. This is when a thin tube with a light source and video camera at one end is inserted up your nose to see inside it.

Other tests may include:

• a nasal inspiratory flow test – where a small device is placed over your mouth and nose to measures the airflow when you inhale through your nose
• a CT scan – a type of scan that uses X-rays and a computer to create detailed images of the inside of the body

Treatment for non-allergic rhinitis often depends on the cause.

In some cases, such as when rhinitis is caused by a viral infection, treatment may not be necessary. This is because the infection responsible for the rhinitis normally clears up within a week or 2.

Otherwise treatment options include:

• avoiding triggers
• changing your medicines
• nasal rinses
• nasal sprays
• stopping overused nasal sprays

Avoiding triggers

You may be advised to avoid possible triggers. For example, it may help to avoid smoky or polluted environments.

Changing your medicines

If your rhinitis is believed to be caused by a medicine you're taking, such as beta blockers, your GP may be able to prescribe an alternative medicine to see if it helps to reduce your symptoms. Do not stop taking any prescribed medicine unless advised to by a doctor.

Nasal rinses

Sometimes, rinsing your nasal passages with a salt water solution can be helpful. This is known as nasal irrigation or nasal douching.

Rinsing your nasal passages helps wash away any excess mucus or irritants inside your nose, which can reduce inflammation and relieve your symptoms.

Nasal irrigation can be done using either a homemade salt water solution or a solution made with sachets of ingredients bought from a pharmacy. Small syringes or pots (which often look like small horns or teapots) are also available to help flush the solution around the inside of your nose.

To make the solution at home, mix a teaspoon of salt and a teaspoon of bicarbonate of soda into a pint of boiled water that's been left to cool to around body temperature (do not attempt to rinse your nose while the water is still hot).

You will probably only use a small amount of the solution. Throw away whatever is left.

To rinse your nose:

• standing over a sink, cup the palm of one hand and pour a small amount of the solution into it
• sniff the water into one nostril at a time – an alternative is to use a syringe to insert the solution into the nose
• repeat this until your nose feels comfortable (you may not need to use all of the solution)

While you do this, some solution may pass into your throat through the back of your nose. Although the solution is harmless if swallowed, try to spit out as much of it as possible.

You can carry out nasal irrigation several times a day. Make a fresh salt water solution each time.

Nasal sprays

Various types of nasal spray relieve the symptoms of non-allergic rhinitis. They include:

• antihistamine nasal sprays – these help to relieve congestion and a runny nose by reducing inflammation
• steroid nasal sprays – like antihistamines, these work by reducing inflammation
• anticholinergic nasal sprays – these reduce the amount of mucus your nose produces, which helps to relieve a runny nose
• decongestant nasal sprays – these relieve congestion by reducing swelling of the blood vessels inside your nose

You can buy many of these sprays from pharmacies without a prescription.

It's important to check the leaflet that comes with them before you use the nasal spray, because they're not suitable for everyone. If you're uncertain whether you should be using one of these medicines, check with your GP or pharmacist.

You should also make sure you check the manufacturer's instructions to see how to correctly use these sprays.

If you use a decongestant spray, do not use it for longer than 5 to 7 days at a time. Overusing decongestants can make congestion worse.

Stopping overused nasal decongestant sprays

Some cases of non-allergic rhinitis are caused by overusing nasal decongestant sprays. In these cases, the best treatment is to stop using these sprays. However, this can be difficult, particularly if you've been using them for some time.

Try not using the spray in your least congested nostril first. After 7 days this nostril should open up, at which point try to stop using the spray in your other nostril.

Some specialists try to gradually switch your spray from a decongestant (which is harmful in the long term) to a steroid spray (which generally can be used for longer).

If you have non-allergic rhinitis, there's a risk you could develop further problems.

These can include problems caused by having a blocked or runny nose, such as:

• difficulty sleeping
• drowsiness during the daytime
• irritability or problems concentrating

The inflammation associated with non-allergic rhinitis can also lead to further health conditions, such as:

• nasal polyps
• sinusitis
• middle ear infections

Nasal polyps

Nasal polyps are fleshy swellings that grow from the lining of your nose or sinuses (the small cavities above and behind your nose), which are caused by inflammation of the membranes of the nose, and sometimes as a result of rhinitis.

They've also been linked with an increased risk of other health conditions, such as asthma, that develop later in life.

Nasal polyps are shaped like teardrops when they're growing and they look like a grape on a stem when fully grown. They vary in size and can be yellow, grey or pink. They can grow on their own or in clusters and usually affect both nostrils.

If nasal polyps grow large enough, or in clusters, they can:

• interfere with your breathing
• reduce your sense of smell
• block your sinuses, leading to sinusitis

Small nasal polyps can be shrunk using steroid nasal sprays so they do not cause an obstruction in your nose. Large polyps may need to be surgically removed.

Read more about treating nasal polyps.

Sinusitis

Sinusitis is a common complication of rhinitis. It's where sinuses become inflamed or infected.

The sinuses naturally produce mucus, which usually drains into your nose through small channels. However, if these drainage channels are inflamed or blocked (for example, because of rhinitis or nasal polyps), the mucus cannot drain away and it may become infected.

Common symptoms of sinusitis include:

• severe facial pain around your cheeks, eyes or forehead
• toothache
• a blocked nose
• a runny nose – your nose may produce a green or yellow mucus either through the nostrils or down the back of the nose (catarrh)
• a high temperature

Symptoms of sinusitis can be relieved using painkillers, such as paracetamol, ibuprofen or aspirin.

However, these painkillers are not suitable for everyone, so make sure you check the leaflet before you take them. For example:

• children under 16 years of age should not take aspirin unless it's recommended by a doctor
• ibuprofen is not recommended for people with asthma or a history of certain stomach conditions, such as stomach ulcers

Speak to your GP or pharmacist if you're unsure.

Antibiotics may also be recommended if your sinuses become infected. In cases of long-term sinusitis, surgery may be needed to improve the drainage of your sinuses.

Read more about treating sinusitis.

Middle ear infections

Middle ear infections (otitis media) can develop as a complication of non-allergic rhinitis.

Rhinitis can cause a problem with the eustachian tube at the back of the nose. If this tube does not function properly, then fluid may accumulate in the middle ear (behind the eardrum) and become infected.

There's also the possibility of infection at the back of the nose spreading to the ear through the eustachian tube.

Symptoms of a middle ear infection can include:

• earache
• a high temperature
• hearing loss
• mild loss of balance

Most ear infections clear up within a couple of days, although paracetamol or ibuprofen can be taken to relieve pain and a high temperature. Antibiotics may also be prescribed if your symptoms persist or are particularly severe.

Read more about treating middle ear infections.