A swollen lymph node in the neck: when does it go down, and when should it be investigated?

Lymph nodes (lymph glands) are the body's filters. Each one collects the lymph fluid coming from a particular area, and when there is an infection in that area, the immune cells inside multiply and make the node bigger. That is why the NHS writes that swollen glands are usually a sign of the body fighting an infection, felt as painful, tender lumps on either side of the neck, under the chin, in the armpits and in the groin. It adds that sometimes a gland swells on only one side.

The nodes in the neck are not a single group. The review in the journal of the American Academy of Family Physicians divides the head and neck nodes into those under the chin, under the jaw, the front and back chains of the neck, in front of the ear and above the collarbone, and writes that the position of a node points to the source according to which area it drains. The nodes under the jaw are covered separately on the page about conditions linked to the mouth and teeth; the subject here is the chains running down the side of the neck and the area above the collarbone.

The commonest cause of swollen neck nodes is ordinary infection. The NHS lists colds, tonsillitis, and ear and throat infections as the commonest causes, viral infections such as glandular fever (infectious mononucleosis, the illness caused by the Epstein-Barr virus) as occasional causes, and serious conditions such as cancer of the blood (leukaemia) and cancer of the lymphatic system (lymphoma) among the rare causes. A dental abscess and gum infection can also make the nodes under the jaw and in the upper neck on the same side swell.

There is a simple check you can do at home to find the source. Write down on a piece of paper where the node is, its size (a lentil, a chickpea, a hazelnut), whether it is painful and whether it slides under the skin when you push it with a finger, and date it. Then look for the source: in the last two weeks, have you had a sore throat, earache, a tooth that hurt or swelled, a sore in your mouth, a sore or spot on your scalp, or a cat scratch? Repeat the same measurement a week later. When you see the doctor, this note lets you show from a record, not a guess, whether the node has got smaller.

There is data that brings the worry down to a realistic size. In a study in the Netherlands of patients who went to their GP with unexplained swollen lymph nodes, the prior probability of a malignant cause came out at 1.1%. The AAFP review reports that this rate rises with age: 4% at 40 and over, and 0.4% under 40. In the same Dutch study, GPs had referred 80% to 90% of the malignant cases to a specialist within four weeks of the first visit.

The position of the node is the single piece of information that changes this probability most. A node felt in the hollow just above the collarbone (a supraclavicular node) is not normally felt. In the Dutch study, a malignant cause was found in half of the nodes in this position; the AAFP review writes that in different studies this rate ranges from 34% to 50%, that people over 40 carry the highest risk, and that this node needs prompt assessment. The NHS likewise asks you to see a doctor about a swollen gland just above or below the collarbone.

The AAFP review gathers the risk factors for a malignant cause in a table: being over 40, male sex, the node lasting longer than four to six weeks, not returning to its original size after eight to twelve weeks, nodes in two or more areas at once, a position above the collarbone, and general symptoms such as fever, night sweats and weight loss. While the review says that a painless, hard, irregular or fixed mass may be malignant, it adds that these features felt by hand cannot reliably tell the difference on their own.

Lymphoma has a sign of its own. The NHS gives the commonest symptom of Hodgkin lymphoma as a painless swelling in the neck, armpit or groin, and lists pain in these glands when you drink alcohol, a high temperature, night sweats, breathlessness, itching and sudden weight loss as other symptoms. NICE, England's national clinical guidance body, recommends considering referral on the suspected cancer pathway for an adult with unexplained lymph node enlargement, also taking these symptoms into account.

Behind a neck node there can also be a tumour starting in the mouth or throat. NICE recommends referral for laryngeal cancer in people aged 45 and over with an unexplained lump in the neck, and, at any age, referral for mouth cancer with a persistent unexplained lump in the neck or a mouth ulcer lasting longer than 3 weeks. The NHS lists a mouth ulcer lasting longer than 3 weeks, a red or white patch in the mouth and a lump in the neck among the symptoms of mouth cancer, and writes that a dentist can also help with these complaints. In other words, someone with a lump in their neck should have their mouth looked at too.

The first list is the typical behaviour of a node reacting to an infection. If even one item from the second list applies, do not wait.

The order deliberately starts with danger. If there is no picture threatening the airway, the assessment works through the node's position, how long it has lasted and its source.

1. 1

   Swallowing and breathing first

   The NHS asks for an urgent GP appointment or a call to 111 when swollen glands come with serious difficulty swallowing or breathing. With glandular fever, if you cannot swallow your own saliva or are seriously short of breath, call 999, which in Turkey means 112. Do not wait either if the floor of the mouth is hardening and the tongue is being pushed up, or the neck is swelling fast.

2. 2

   The history: how long, and with what?

   The clinician asks how long the node has been there, whether it has grown or got smaller, about infections in recent weeks, dental complaints, a high temperature, night sweats, weight loss, itching, smoking and alcohol, contact with animals and travel. The dated note you have kept is useful here.

3. 3

   Examination: position, size, firmness, mobility

   The chains in the neck, above the collarbone, the armpits and the groin are felt, and the clinician checks whether there are nodes in more than one area. The AAFP review counts a node larger than 1 centimetre or with a changed consistency as abnormal. The inside of the mouth, the tongue, the tonsils and the teeth are examined too.

4. 4

   If there is a clear source: treatment and monitoring

   If a throat, ear or tooth infection has been found, that is treated and the node is monitored. The AAFP review writes that if the history and examination do not suggest a malignant cause, a node in a single area can be watched for four weeks.

5. 5

   If it cannot be explained or there is risk: tests

   A blood count and infection tests, an ultrasound scan of the neck and, if needed, sampling with a fine needle or a core needle (biopsy) are done. The AAFP review writes that the diagnostic accuracy of fine needle biopsy approaches 90% in adults, but that it can fall short in lymphoma because it cannot show the structure of the node.

6. 6

   Referral according to the result

   Monitoring if it is an infection or a reactive node; haematology if lymphoma is suspected; ENT or oral and maxillofacial surgery if a tumour starting in the mouth or throat is suspected. Questions to ask: how many centimetres is the node, when will it be looked at again, and what is the next step if it does not go down?

It is not the swollen lymph node itself that is treated but its cause. What is done depends on why the node has swollen.

The points below are wrong decisions often made with this complaint. We set them out so that you can ask the right questions whichever clinician you see.

The time depends on the cause. The course below applies to a node reacting to an infection; the plan of the clinician following you takes priority.

1. The first week

   As the infection recedes, the node becomes less tender. The NHS asks you to see a doctor about a gland that has not got smaller within 1 week or is growing.

2. 1 to 2 weeks

   The NHS writes that glands swollen by an infection usually go down on their own within 1 to 2 weeks. Even if the node does not disappear completely, it is expected to get noticeably smaller.

3. 2 to 4 weeks with glandular fever

   The NHS writes that with this illness recovery starts within 2 to 4 weeks, but the picture can last for weeks.

4. 4 weeks and beyond

   The AAFP review counts a node that lasts longer than four to six weeks and does not return to its original size within eight to twelve weeks among the risk factors. At this point, an ultrasound scan and, if needed, a biopsy should be discussed.

We do not give a single figure here, because behind a swollen node in the neck there may be a throat infection that passes in a few days, a tooth that needs treating, or a picture that calls for an ultrasound scan and a biopsy. These are the items that determine the scope:

The cause of the node

An infection, a dental source, long-lasting benign causes and lymphoma or a tumour are completely different routes and the field of different clinicians.

The need for tests

For most nodes, an examination and monitoring are enough; for an unexplained node, blood tests, an ultrasound scan and a biopsy are added.

Treating a dental source

If the source is a tooth, root canal treatment, extraction or gum treatment enters the plan as a separate item.

The length of monitoring

The number of follow-up examinations needed to see whether the node is going down varies from person to person.