Cough
June 2020
Coronavirus and cough
2020 has been dominated all over the world by the coronavirus (COVID-19) pandemic.
One of the main symptoms of coronavirus is a new, continuous coughi – in other words, three or more episodes of coughing in 24 hours or repeated coughing for more than an hour.

Some people who have a long-term cough might find that they are coughing more than usual.

Other common symptoms of coronavirus includei:

A fever (raised temperature when you check it or feeling hot to touch on your back or chest).
A loss of, or change to, your sense of smell or taste. Some people lose their sense of smell entirely, while others find things smell or taste different compared to how they usually do.
If you have any of these symptoms, you need toi:
1) Self-isolate. This means staying at home and isolating yourself from everyone else, including people you live with.
2) Get a test by using the NHS online tool.
3) Make sure everyone you live with, and anyone in your ‘support bubble', also self-isolates.
why do we
cough

We need oxygen to stay alive and we get that oxygen from the air. When we breathe in, oxygen-rich air passes into the tiny balloons (called alveoli) in our lungs, where oxygen is picked up by tiny blood vessels called capillaries and carried in the blood to supply our organs.

Air needs to come into very close contact with the blood vessels for the oxygen to pass across, so the walls of the alveoli are very thin. Dust, mucus which has dripped down the back of the throat from the nose, mucus produced by the airways, germs and inflammation can all block the alveoliii. This can interfere with that gas exchange – and coughing is designed to clear anything that gets in the way of getting oxygen into the bloodii, i,ii.

However, if you cough too much, it can not only spread germs but also seriously interfere with your lifeii, ii. In many cases, there's nothing to bring up, so coughing doesn't serve a useful purposeiii. And too much coughing can also damage the delicate structures of the lung.

how do
COUGHS HAPPEN?ii

Every schoolchild knows that if you tap someone below the knee, their lower leg jerks out – this is known as a reflex. Cough is also caused by a reflex. Receptors on the walls of the back of the throat and airways send a signal if they're stimulated – either by something touching them or by heat, acid etc. This message is passed to a cough centre in the brain: this in turn sends messages to the muscles of the chest, diaphragm and throat instructing them to contract rapidly.

Sometimes you can suppress a reflex to an extent by actively trying, but we all know that feeling of a tickle in the back of your throat that makes it really hard not to cough.

what causes
cough?iv

Most coughs are 'acute' – officially an 'acute' cough is gone within three weeks. These are usually caused by viral infections like colds or flu (or, of course, coronavirus). Acute cough due to a viral infection is the most common cause of coughv and a cough due to a viral infection may last for 3- 4 weeksv.

A 'subacute' cough lasts from 3-8 weeks. These also tend to be caused by infection: some infections, like whooping cough, can cause a cough that lasts for weeks after the initial illness has settled.

A 'chronic' cough is any cough that lasts for more than 8 weeks. There is a range of causesiv, such as:

Some medications, such as ACE inhibitors used to treat high blood pressure.
Smoking and exposure to cigarette smoke.
Asthma.
Persistent mucus dripping down the back of the throat.
Acid from the stomach ‘refluxing' into the back of the throat, especially when you lie flat.
Allergies such as hay feverv.
how common is
cough?

Coughs are really common. Cough is the most common reason for people to see a doctor vi and accounts for up to 2 in 5 people seeing a chest specialist as an outpatient ii.

It's important to remember that most coughs are caused by a viral infection of the upper airways. At the moment, it's essential to get tested for coronavirus if you have a new cough. However, if your test is negative, there's usually no need to see a doctor v unless you have any of the symptoms or risk factors below. Your pharmacist can help with advice and products to relieve your symptoms.

Up to 1 in 6 people taking ACE inhibitors develop a chronic cough at some pointvi. If your doctor thinks this may be the cause, they may suggest changing you to an alternative medication. It's important not to stop any regular medication without speaking to your doctor.

when
sould i worry?
There are certain ‘red flags' which would make your doctor suspicious of more serious medical problemsvii, viii.
You should always contact your doctor if you have a cough as well as:
Chest pain.
Feeling tired (for longer than you would expect with a simple cold).
Weight loss (when you're not trying to lose weight) or being off your food.
Shortness of breath, especially when you lie flat.
Swelling of your ankles.
Coughing up blood.
Persistent hoarse voice.
Fever that doesn't settle.
Problems swallowing.
Vomiting because of your coughing.
If you're a smoker and you're over 40, or if you're over 55 and have quit within the last 15 years, you should see your doctor if you have a cough for any length of timevii.
what can i do about goughix?

As we've already heard, most coughs are caused by a viral infection. That means antibiotics – which only work against bacterial infections – won't help. The exceptions are if you have any of the ‘red flags' above, feel very unwell in yourself or have other conditions that put you at higher risk of complicationsix.

But that doesn't mean you have to suffer in silence (or rather, noisily) - there's plenty you can do to relieve your symptoms in the meantime.

For all acute coughsv
Fighting off a viral infection can take a lot of energy, so make sure you get plenty of rest.
Do drink plenty of non-alcoholic fluids – if you're sweating a lot, you're more prone to dehydration, which can leave you feeling more tired and headachy.
If you're generally achy or have a sore throat, paracetamol or ibuprofen can help.
Dry, tickly cough v
For over 1 year-olds, try hot lemon and honey.
Your pharmacist can advise on cough syrups or sweets that help coat the throat, relieving irritation.
Chesty coughtv
An 'expectorant' cough preparation can help you get rid of excess mucus produced when you have a chesty cough. Products containing guaifenesin, for instance, can make mucus less sticky, allowing you to cough it up more easilyix.

Lemsip Cough for Chesty Cough Oral Solution'x and LemsipMax All in Onexi both contain guaifenensin. Products containing guaifenesin are only suitable for over 12 year-olds. Always read the label.

SOURCES:

i NHS UK. Check if you or your child has coronavirus symptoms. Available at https://www.nhs.uk/conditions/coronavirus-covid-19/symptoms/ last accessed 18/6/2020

ii Polverino M et al. Anatomy and neuro-pathophysiology of the cough reflex arc. Multidisciplinary Respiratory Medicine 2012, 7:5 http://www.mrmjournal.com/content/7/1/5.

iii Canning B et al. Anatomy and Neurophysiology of Cough: CHEST Guideline and Expert Panel Report. CHEST 2014; 146 ( 6 ): 1633 – 1648.

iv National Institute for Health and Care Excellence/Clinical Knowledge Summaries. Cough – types and causes. Available from https://cks.nice.org.uk/cough last accessed 12/7/2020.

v NHS UK Cough. Available from https://www.nhs.uk/conditions/cough/ - last accessed 13/7/2020.

vi National Institute for Health and Care Excellence/Clinical Knowledge Summaries. Cough – how common is it? Available from https://cks.nice.org.uk/cough#!backgroundSub:2 - last accessed 13/7/2020.

vii National Institute for Health and Care Excellence/Clinical Knowledge Summaries. Cough – diagnosis. Available from https://cks.nice.org.uk/cough#!diagnosisSub last accessed 14/7/2020.

viii National Institute for Health and Care Excellence. Suspected cancer: recognition and referral. NICE guideline NG12. 23 June 2015.

ix National Institute for Health and Care Excellence Clinical Knowledge Summaries. Cough – management. Available from https://cks.nice.org.uk/cough#!scenariolast accessed 14/7/2020

x Lemsip Cough Chesty. Summary of Product Characteristics. Medicines.org.uk/emc . Available from https://www.medicines.org.uk/emc/product/616/smpc#PHARMACOLOGICAL_PROPS last accessed 14/7/2020

xi Lemsip Max All in One Lemon. Summary of Product Characteristics. Medicines.org.uk/emc . Available from https://www.medicines.org.uk/emc/product/2763/smpc last accessed 14/7/2020