This site is intended for health professionals only

PHE: Green phlegm does not need antibiotics

Patients who ask for antibiotics to combat green phlegm or snot need to be made aware that they are not always signs of infection. 

Research from Public Health England's (PHE) primary care unit has found that 40% of the general public believe antibiotics would clear a cough with green phlegm but only 6% believe the medicine would work for a cough with clear phlegm. 

But differing types of white blood cells, which are produced by the body to attack pollutants, dirt or microbes, cause the colour. 

Therefore, coloured phlegm does not mean a patient will need antibiotics. 


Dr Cliodna McNulty, head of PHE's primary care unit said: “It's a prevailing myth that anyone with green phlegm or snot needs a course of antibiotics to get better. 

“Most of the infections that generate lots of phlegm and snot are viral illnesses and will get better on their own, although you can expect to feel pretty poorly for a few weeks.” 

Dr McNulty recommends over-the-counter medication to manage the symptoms of these illnesses. 

Problems of antibiotic resistance are growing, according to Dr McNulty. Everyone can help by not using antibiotics for the treatment of uncomplicated infections.

Dr McNulty said: “Many people have a good understanding of what antibiotic resistance is but when it comes to their own illnesses still believe that antibiotics can help to treat what can be severe cold and flu symptoms. 

“This is not the case and we must get away from believing this to preserve these precious medicines for when we really need them.”

Newly appointed Royal College of General Practitioners chair Dr Maureen Baker, said the results are not very surprising. 

She said: “Overuse of antibiotics is a serious public health concern and a clinical priority for the RCGP. Infections adapt to antibiotics used to kill them and can ultimately make treatment ineffective, so it's crucial that antibiotics are used appropriately.”