Thyroid nodule

A nodule is a localised lump in the thyroid, the gland at the front of the neck. Nodules are very common and become even more common with age, and they are found more often in women than in men. The great majority of them are not cancerous.

Many nodules are discovered by chance, during an ultrasound of the neck arteries, an imaging test for something else, or when the neck is felt during an examination. That is why the first step after discovery is assessment, not worry: it needs to be established whether the nodule affects how the thyroid works and whether it has features that call for further evaluation.

How you notice it

Most nodules cause nothing at all. When they are larger, they show as a visible or palpable swelling at the front of the neck that moves upwards when you swallow.

With larger or awkwardly placed nodules, there may be a feeling of pressure or a lump in the throat, difficulty swallowing larger mouthfuls, and less often a cough or a feeling of tightness in the neck when lying on your back.

Some nodules produce thyroid hormones and work independently of the body's control. In that case the main symptoms are a pounding heart, trembling hands, sweating, restlessness, insomnia and weight loss despite an unchanged appetite. Less often, nodules appear alongside autoimmune inflammation with signs of an underactive thyroid: tiredness, feeling cold, constipation and weight gain.

What affects the risk

Nodules develop more often in women, with age, when there is too little iodine in the diet and when thyroid disease runs in the close family. These are factors for developing a nodule, not for it being cancerous.

Circumstances that increase the likelihood that a nodule is not benign include radiation to the neck or head in childhood and thyroid cancer in a first-degree relative. Being very young or very old at the time of discovery also matters.

A nodule that grows quickly, is hard and does not move, and is accompanied by enlarged lymph nodes in the neck or hoarseness needs to be seen as a priority.

When not to delay

Book an appointment soon if a lump in the neck grows noticeably within a few weeks, if hoarseness lasts more than three weeks, if you have difficulty swallowing, or if you can feel enlarged lymph nodes in the neck alongside the nodule.

You need emergency help if you have difficulty breathing, a whistling sound when breathing in, or a rapidly growing, painful swelling of the neck. If your breathing is getting worse, do not wait for an appointment; call 112.

Calling 112 also applies to severe signs of an overactive thyroid: a high fever with confusion, a very fast and irregular pulse, vomiting and marked weakness. This condition is rare but dangerous.

Do not watch a palpable lump in the neck for months in the hope that it will go away. The assessment is quick and, for the great majority of people, reassuring.

How a nodule is assessed

First, thyroid function is checked with a laboratory test, mainly TSH, and if needed also thyroid hormones and antibodies. The result shows whether the nodule affects your metabolism and guides what comes next.

This is followed by an ultrasound of the neck. It shows the size, number and make-up of the nodules and their features: edges, internal structure, blood flow and tiny calcifications. It is these features, and not size alone, that decide whether further evaluation is needed.

When it is needed, a fine-needle aspiration is performed. The cell sample is examined by a cytopathologist. When TSH is low, a scintigraphy scan may also be considered to find out whether the nodule is working independently; the doctor will explain where this test is carried out.

Bring previous results with you. Comparing the ultrasound with last year's tells more than a single report.

What happens after the assessment

For most people, monitoring is agreed, with a follow-up ultrasound and laboratory test at an interval set by the doctor according to the features of the nodule. No treatment is needed at that point.

When a nodule causes an overactive thyroid, the options are medicines, radioactive iodine treatment or surgery. The choice depends on age, the size of the nodule and other conditions.

Surgery is considered when the cytology result raises suspicion, for large nodules pressing on the windpipe or gullet, and for nodules that grow markedly despite monitoring.