The truth about mucus
"It's not just the volume that's important, it's also the consistency," Mr Hern says. Healthy mucus has certain characteristics. "Mostly it's clear, thin and watery that the cilia can move around. If you get a cold and it becomes thick, sticky, and viscous, that's often too much for these cilia to clear. It can hang around in your nose and sinuses. It can become thick and coloured and nasty and lead to symptoms," Mr Hern says.
Mucus colour changes
Seeing mucus change colour can be a concern. "People think that's more significant than it is," Mr Hern says. "Most mucus is clear when you're healthy. When you have a viral infection it's often thickening up and often yellow."
Sometimes mucus turns green. "Patients often think they've developed a bacterial infection, but that's not necessarily the case. It can be green even if it's just a viral infection.
"This is a common misconception for patients and indeed for doctors, who might prescribe antibiotics if the patient's got very green, viscous mucus." Antibiotics are used to treat bacterial infections, not viral ones like a cold or flu.
Doctors and ENT specialists use an instrument called an endoscope to look into the nose and sinuses. "With bacterial sinusitis, more often than not, the discharge is white."
Mucus problems beyond the common cold
Mucus with a cold is usually just a mild and fairly short-lived inconvenience. However, Mr Hern says some patients have chronic catarrh, post nasal drip, mucus in the nose and throat "that goes on and on, day-after-day, without any respite."
For problems like these, old-fashioned treatments are still effective: "We try to get patients to flush their nose with salt water so they decrease the viscosity [thickness] of mucus."
This helps get the flow of mucus moving normally again. "Nasal saline douching can have a very beneficial effect."
Mr Hern says doctors may recommend devices to produce a mist of saline, squeezy bottles filled with cooled boiled water with saline solution added, or Neti pots. "It's perhaps an older fashioned treatment that's had a bit of a revival."
He says for patients with longer-term sinus problems: " Decongestants, generally, aren’t very helpful." He says they're only designed for treatment lasting around five to seven days. He says there can be a rebound from decongestant treatment over a longer period: "If you keep using decongestant for a long period of time, you can actually make your nose quite congested."
Nasal steroid sprays are another treatment option in some cases.
Does mucus get a bad name?
So, with mucus being an essential part of nose and sinus health, does the 'yuck factor' give it a bad name? "Probably," Mr Hern tells us. "People don’t appreciate that it has a protective function and keeps the nose and throat nice and moist. Most of us don't even notice this process of mucus transportation is going on."
There are some rare conditions in which people don’t have any nasal mucus, called atrophic rhinitis. "Patients are in all sorts of problems. Their nose becomes extremely dry and crusted."
"People don’t really understand the benefits of nasal and sinus mucus. It's only brought to their attention if there's a problem. So you could say it's got a bit of a bad name.
"For most people, for most of the time it's having a very positive effect, but we don’t really know about it."
Titles and opinions were correct at time of original publication.