Persistent sore throat: causes, when to see a GP and what tests involve

Almost everyone gets a sore throat from time to time. The NHS describes sore throats as very common and usually nothing to worry about, with most getting better by themselves within a week. A sore throat is considered persistent when it lasts longer than that, or when episodes keep coming back.

The throat can feel painful, especially when swallowing, dry or scratchy, and the back of the mouth may look red. The NHS also lists bad breath, a mild cough and swollen neck glands as common features. Because so many different conditions share these symptoms, the pattern over time is what helps work out the cause.

The NHS says sore throats are usually caused by viruses such as colds and flu, or by smoking, and only very occasionally by bacteria. Other causes it lists are laryngitis, tonsillitis, strep throat and glandular fever.

Tonsillitis is an infection of the tonsils at the sides of the throat. The NHS says it usually goes away after 3 to 4 days but can last longer, and that it is most often viral. Repeated bouts are one of the reasons people are referred to ENT, although the NHS notes that having the tonsils removed is very rarely needed and is usually considered only for severe tonsillitis that keeps coming back.

Glandular fever, a viral infection mostly affecting teenagers and young adults, can cause a sore throat with swollen glands, a high temperature and marked tiredness. The NHS says you should start to feel better within 2 to 4 weeks, and a GP may arrange a blood test.

Acid reflux can also irritate the throat. The NHS lists a hoarse voice, a sour taste in the mouth, and a cough or hiccups that keep coming back among its symptoms, and says symptoms are often worse after eating, when lying down and when bending over.

The NHS gives clear thresholds. See a GP if your sore throat does not improve after a week, if you often get a sore throat, if your child is under 5 and needs help for a sore throat, or if you have a sore throat together with a lump in your mouth or neck or a mouth ulcer lasting more than 3 weeks.

Ask for an urgent GP appointment or call NHS 111 if you or your child have a sore throat and you are worried, have a very high temperature or feel hot, cold or shivery, show signs of dehydration such as peeing less or dark pee, or have a weakened immune system, for example because of diabetes or chemotherapy.

Call 999 or go to A&E if there is difficulty breathing, an inability to swallow, drooling, a high-pitched sound when breathing (stridor), or severe symptoms getting worse quickly. For tonsillitis, the NHS also lists swelling inside the mouth and throat, difficulty speaking and difficulty opening the mouth as possible signs of quinsy, an abscess behind the tonsil.

A GP will usually ask about how long the symptoms have lasted, whether there is fever, swallowing difficulty, voice change, smoking and reflux symptoms, and will look in your throat and feel your neck. The NHS says that for tonsillitis a doctor can usually tell by asking about symptoms and looking in the throat, and may arrange a swab to see if bacteria are causing it, or a blood test for glandular fever if symptoms are severe or will not go away.

If a persistent sore throat does not have a clear explanation, the GP may refer to an ear, nose and throat (ENT) service for a closer look at the throat, particularly where there is a lump, a long-lasting ulcer, voice change or difficulty swallowing. The NHS notes that these features alongside a sore throat should be assessed.

Treatment depends on the cause. For symptom relief, the NHS suggests gargling with warm salty water (not for children), drinking plenty of water, eating cool or soft foods, avoiding smoking or smoky places, sucking ice cubes or lollies (not small hard items for young children) and resting. A pharmacist can suggest paracetamol or ibuprofen and medicated lozenges. The NHS says anaesthetic sprays have little proof of helping on their own.

Antibiotics are only given if a bacterial infection is possible. The NHS says a pharmacist can give the same antibiotic treatment as a GP for a sore throat if you need it, for people aged 5 or over. If reflux is the likely cause, treatment of reflux through lifestyle changes, antacids or alginates, or a proton pump inhibitor from a GP may help the throat symptoms.

The large majority of persistent sore throats have a benign cause and settle once it is treated or runs its course. The reason for assessment is to make sure the uncommon causes are not missed.

On the NHS, the route is pharmacist or GP first, with ENT referral when needed. Some people choose a private ENT consultation for faster access to an examination of the throat with a camera. The assessment is the same in principle, and a GP letter can still be useful to share your history.