Introduction
Pain in the thyroid gland is caused by irritation of the sensitive nerves, the superior laryngeal nerve and the recurrent laryngeal nerve, both of which originate from the large and important vagus nerve. A sensitive pain nerve is triggered by various stimuli. This process is called nociception in the technical language.
The corresponding receptors are called nociceptors and are located in practically every tissue. They are sensitive to different qualities: mechanical stimuli, extreme thermal stimuli (extreme heat and cold) and chemical stimuli (e.g. bell pepper pungency). They are also activated by inflammatory substances, which explains why inflamed areas are always painful.
Inflammation of the thyroid gland can therefore cause pain, as can manipulative surgery. The stimuli are then transmitted to the brain via ascending pathways. This is where the conscious perception, the pain, is created. The most feared cause of cancer, however, is not painful.
Causes
Usually, the thyroid gland is operated on when a suspicious node has to be removed or the thyroid gland has grown so large that the surrounding structures are affected. After each operation, there is rather mild and rarely severe pain in the corresponding surgical area. However, this is not only due to irritation of the thyroid nerve, but also because other tissues had to be cut in order to reach the thyroid gland.
Pain after thyroid surgery therefore also comes from the skin, subcutaneous tissue and connective tissue. It is mainly the mechanical irritation and the inflammatory substances that irritate the nerves of the thyroid gland. Postoperative pain (pain after an operation) can be aggravated by psychological stress, personal perception and classification of painful experiences, inflammation in the area of the operation or insufficient administration of painkillers.
As a rule, the pain medication Novalgin® (active ingredient: metamizole) is given after surgery. This is a very potent painkiller that is used to treat stronger pain. Persistent pain together with hoarseness and voice changes should be examined by a doctor.
Puncture is also an invasive (injurious) procedure, but its area is much smaller. There should be only minor pain. The most common reason for a thyroid biopsy is a suspicious lump.
In this case, a fine needle puncture is usually performed. The thyroid gland lies under the larynx. A branch of the nerve N. laryngeus superior (which supplies the thyroid gland) sensitively innervates the upper part of the larynx.
Because of the close relationship between the two organs, a patient cannot say for sure whether his pain is coming from the thyroid or the larynx. An inflammation of the larynx (laryngitis, epiglottitis) can have many causes, often associated with infections and colds, but also overstrain (vocal and speech organs!). Laryngitis practically does not affect the thyroid gland.
This nerve does not run in the middle of the body, but has a right and left counterpart. Therefore it is theoretically possible that only one side reports pain. This can occur after an operation where only one side of the thyroid gland has been removed.
An accidental (idiopathic) inflammation of the single nerve is not known so far. Pain in hypothyroidism (hypothyroidism) is very rare. The causes of hypothyroidism are congenital or acquired.
Acquired causes are, for example, medications or operations (here, post-operative pain can of course occur again), autoimmunological processes (the immune system turns against its own structures) or malfunction of certain areas of the brain that control thyroid function. The metabolic changes may cause pain in the legs, arms and chest area. These are due to changes in the skeletal and muscle areas.
They occur very rarely. Nodules may be noticeable during the palpation examination. A grossly painless lump should always be clarified quickly, as thyroid cancer can manifest itself in this way.
Nodules are usually already visible in ultrasound, but their significance can only be assessed by scintigraphy. A scintigraphy is used to examine the functional state of the thyroid gland tissue. For this purpose, a low-level radioactive substance (Technetium Tc-99m) is injected, with the help of which the thyroid gland glows in different colors in the imaging.If an area does not accumulate or accumulates little, one speaks of cold knots.
These are malignomsuspekt, i.e. a cancer suffering should be excluded or proven in the following. Hot nodules indicate an overfunction in a described area. If the thyroid gland accumulates over a large area, it is probably a completely different thyroid disease, Graves’ disease.
Warm nodules, which indicate an autonomy of the thyroid tissue, can be examined more closely with the hormone administration of T3 and T4. Via negative feedback, these signal the brain to stop producing more TSH (which stimulates the thyroid gland). If the warm nodes continue to glow warmly, this is proof that they are working independently of the brain.
This is called thyroid autonomy. This examination is called suppression scintigraphy. If a cold node is present, other things may also be responsible: cysts, inflammation, bleeding, scarring or calcification.
In this case, a further examination, the biopsy (sampling), is necessary. If the thyroid gland is swollen, it is called a goiter or goiter. The most common cause (90%) of goiter is iodine deficiency, which is particularly prevalent in our latitudes (diet low in fish!).
The iodine deficiency causes hyperplasia of the thyroid cells, i.e. an increase in the number of cells without an increase in cell size. This causes the entire thyroid gland to swell, but the hormonal functions of the thyroid gland are not affected. More rarely, the thyroid gland malfunctions leading to goiter.
For example, cysts, Graves’ disease (an overactive gland), a brain tumor (which produces too much TSH and causes the thyroid gland to grow secondarily) or malignant diseases. These can be tumors in the thyroid gland itself or metastases (spread) of other cancers. A goiter has to become very large to make swallowing, breathing or other problems.
Then an operation is necessary to relieve it. The iodine-deficient goiter can be easily cured by iodine therapy and shows signs of regression. Hashimoto’s thyroiditis is an inflammation of the thyroid gland caused by the body’s own immune system (autoimmune disease). Its symptoms are similar to those of normal hypofunction. Rarely, affected patients can report a past phase during which they noticed swelling in the throat or difficulty swallowing.
