Thyroid Nodule

The thyroid gland sits in the middle of the lower neck, just in front of the windpipe, at the level of the collarbones. Its job is to produce thyroid hormone, which controls the metabolism, meaning the way the body uses energy.

A thyroid nodule appears when the thyroid tissue grows and forms a small swelling in one limited area. Some nodules are solid and some hold fluid. A nodule that holds only fluid is called a cyst.

Thyroid nodules are not the same as goitre. Goitre is abnormal enlargement of the whole gland. A person with goitre can have thyroid nodules as well.

The first tests

If you think you have a thyroid nodule, see a doctor for a first examination. The first step is usually blood tests, which show how much thyroid hormone is being produced. An ultrasound examination alongside them shows the size, the number and the position of the nodules.

How common they are

The chance of having a thyroid nodule rises with age. From the age of 50 onwards, almost half of people have them. By the nineties, having at least one is entirely ordinary.

In healthy people with no complaints at all, ultrasound finds thyroid nodules in up to 76 per cent. Most people therefore have a nodule without knowing it.

Hot and cold nodules

Some nodules produce more thyroid hormone than normal. These are called hot nodules. In general, hot nodules rarely turn into cancer.

Most nodules produce no extra hormone. These are called cold nodules.

Some nodules go unnoticed while they are small. Others grow until they press on or push the windpipe or the gullet.

Ultrasound and biopsy

Neck ultrasound is the best method for examining the size and the shape of a thyroid nodule. Size matters in following a nodule.

Apart from special cases, a biopsy, which means taking a small piece of tissue for examination, is generally not needed for nodules under 1 centimetre. Most nodules need no biopsy at all. Some need following with ultrasound at regular intervals.