[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Head and neck](https://durgical.com/en/anatomy/region/head-and-neck/) › Thyroid gland [Endocrine system](https://durgical.com/en/anatomy/system/endocrine-system/) · [Head and neck](https://durgical.com/en/anatomy/region/head-and-neck/) # Thyroid gland The thyroid gland is a butterfly-shaped gland at the front of the neck below the larynx; it makes hormones that set the body's metabolism. [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=head_neck&select=thyroid_gland&side=r) Opens in the Durgical app, no sign-up needed. ## What it is A butterfly-shaped gland wrapped around the front of the trachea below the larynx. ## What it does Makes thyroid hormones that set the body's metabolism. ## Key points - Enclosed by the pretracheal fascia and tied to the larynx and trachea, so the gland and any thyroid swelling move up on swallowing - Develops from the foramen caecum at the [tongue](https://durgical.com/en/anatomy/tongue/) base and descends along the thyroglossal duct; a thyroglossal duct cyst is a midline lump near the [hyoid bone](https://durgical.com/en/anatomy/hyoid-bone/) that rises when the tongue is pushed out - The recurrent laryngeal nerve runs in the groove between trachea and oesophagus behind each lobe, near the [inferior thyroid artery](https://durgical.com/en/anatomy/inferior-thyroid-artery/) and Berry ligament: the key structure guarded in thyroidectomy - Iodine deficiency is the classic cause of goitre worldwide, historically common in inland mountain regions, including parts of the Andes, before iodised salt ## Key facts **Where** Anterior neck at C5–T1; isthmus over tracheal rings 2–4 **Blood supply** Superior and inferior thyroid arteries (± thyroid ima) **Nerve** Sympathetic (vasomotor); TSH controls secretion **Function** T3, T4 (metabolism), calcitonin ## Relations **Superficial** Infrahyoid (strap) muscles: [sternohyoid](https://durgical.com/en/anatomy/sternohyoid-muscle/) and [sternothyroid](https://durgical.com/en/anatomy/sternothyroid-muscle/), with the [sternocleidomastoid](https://durgical.com/en/anatomy/sternocleidomastoid-muscle/) further out **Behind** [Parathyroid glands](https://durgical.com/en/anatomy/parathyroid-glands/) on the back of each lobe; the [recurrent laryngeal nerve](https://durgical.com/en/anatomy/recurrent-laryngeal-nerve/) in the tracheo-oesophageal groove **Medial** Larynx and [trachea](https://durgical.com/en/anatomy/trachea/), bound to it by the suspensory (Berry) ligament; [pharynx](https://durgical.com/en/anatomy/pharynx/) and oesophagus further back **Lateral** [Carotid sheath](https://durgical.com/en/anatomy/carotid-sheath/) with the [common carotid artery](https://durgical.com/en/anatomy/common-carotid-artery/), [internal jugular vein](https://durgical.com/en/anatomy/internal-jugular-vein/) and [vagus nerve](https://durgical.com/en/anatomy/vagus-nerve/) **Above** Upper poles reach the oblique line of the [thyroid cartilage](https://durgical.com/en/anatomy/thyroid-cartilage/); the external laryngeal nerve runs close to the [superior thyroid artery](https://durgical.com/en/anatomy/superior-thyroid-artery/) here **Below** Lower poles reach about the sixth tracheal ring; a large goitre can extend behind the [sternum](https://durgical.com/en/anatomy/sternum/) (retrosternal goitre) ## How to find it From behind the seated person, with the neck slightly bent forward, the fingers rest either side of the trachea below the [cricoid cartilage](https://durgical.com/en/anatomy/cricoid-cartilage/); when the person swallows water, the lobes and any nodule rise under the fingers. ## Examination - Swallowing: a thyroid swelling rises with the larynx; a thyroglossal duct cyst also rises when the tongue is pushed out - Pemberton sign: raising both arms above the head flushes the face if a retrosternal goitre crowds the thoracic inlet ## On imaging Ultrasound is the first test: size, solid or cystic, margins, calcifications and blood flow of nodules, and guidance for fine-needle aspiration. Radionuclide scans show hot or cold nodules and ectopic thyroid tissue. ## Common problems - Nodules: very common; most are benign. - Overactive (hyperthyroidism) or underactive (hypothyroidism) gland. - Goitre: an enlarged gland; thyroid cancer. ## How it is diagnosed Blood tests (TSH, T4), ultrasound and a fine-needle biopsy of suspicious nodules. ## Treatment - Thyroid hormone tablets for hypothyroidism; antithyroid medicines or radioactive iodine for hyperthyroidism. - Thyroidectomy (removing part or all of the gland) for cancer, large goitres or some hyperthyroidism. ## Clinical notes - Hyperthyroidism (e.g. Graves disease, toxic nodules) and hypothyroidism (e.g. Hashimoto thyroiditis, iodine deficiency) are the two functional extremes - Thyroidectomy risks: recurrent laryngeal nerve (hoarseness), external laryngeal nerve (loss of high notes), parathyroids (low calcium) and a neck bleed that can press on the airway - Thyroid veins: the superior and middle veins end in the internal jugular vein; the middle vein is short, has no companion artery and is tied first when the lobe is lifted; the inferior veins form a plexus in front of the trachea that bleeds in a low tracheostomy ## Anatomical variants - Pyramidal lobe rising from the isthmus toward the hyoid bone, a remnant of the thyroglossal duct; common - Lingual thyroid at the tongue base when descent fails; it may be the only thyroid tissue present - Thyroid ima artery from the [brachiocephalic trunk](https://durgical.com/en/anatomy/brachiocephalic-trunk/) or [aortic arch](https://durgical.com/en/anatomy/aortic-arch/) in a minority, at risk in a low tracheostomy - Absent isthmus in some people ## Development Endoderm at the foramen caecum descends in front of the hyoid bone and larynx; the calcitonin-making parafollicular (C) cells come from the ultimobranchial body of the fourth pharyngeal pouch. ## Related conditions - [Hypothyroidism](https://durgical.com/en/conditions/hypothyroidism/) - [Graves disease (hyperthyroidism)](https://durgical.com/en/conditions/graves-disease/) - [Thyroid nodule](https://durgical.com/en/conditions/thyroid-nodule/) - [Thyroid cancer (papillary)](https://durgical.com/en/conditions/thyroid-cancer/) - [Goitre](https://durgical.com/en/conditions/goitre/) - [Thyroid storm](https://durgical.com/en/conditions/thyroid-storm/) - [Myxoedema coma](https://durgical.com/en/conditions/myxoedema-coma/) - [Hypoparathyroidism (incl. post-thyroidectomy hypocalcaemia)](https://durgical.com/en/conditions/hypoparathyroidism/) - [Thyroiditis (subacute, painless and postpartum)](https://durgical.com/en/conditions/thyroiditis/) - [Multiple endocrine neoplasia (MEN 1, 2A, 2B)](https://durgical.com/en/conditions/multiple-endocrine-neoplasia/) - [Medullary thyroid carcinoma](https://durgical.com/en/conditions/medullary-thyroid-carcinoma/) - [Euthyroid sick syndrome (non-thyroidal illness)](https://durgical.com/en/conditions/euthyroid-sick-syndrome/) - [Follicular, oncocytic (Hürthle cell) and anaplastic thyroid carcinoma](https://durgical.com/en/conditions/follicular-oncocytic-and-anaplastic-thyroid-carcinoma/) - [Autoimmune polyendocrine syndromes (APS-1, APS-2) and IPEX](https://durgical.com/en/conditions/autoimmune-polyendocrine-syndromes-and-ipex/) - [Thyroglossal duct cyst and branchial cleft cyst](https://durgical.com/en/conditions/thyroglossal-duct-cyst-and-branchial-cleft-cyst/) - [Vocal fold paralysis (recurrent laryngeal nerve injury)](https://durgical.com/en/conditions/vocal-fold-paralysis/) - [Congenital hypothyroidism](https://durgical.com/en/conditions/congenital-hypothyroidism/) ## Test yourself Think of the answer, then tap the question to see it. ## Why does a thyroid swelling move up on swallowing? The thyroid gland is enclosed by the pretracheal fascia and tied to the larynx and trachea, so it rises with the larynx. ## How is a thyroglossal duct cyst told apart from other thyroid swellings on examination? It is a midline lump near the hyoid that also rises when the tongue is pushed out, a remnant of the gland's descent from the foramen caecum. ## Which nerve lies behind each thyroid lobe and is the key structure guarded in thyroidectomy? The recurrent laryngeal nerve, in the tracheo-oesophageal groove near the inferior thyroid artery and Berry ligament; injury causes hoarseness. ## What is the Pemberton sign? Facial flushing when both arms are raised above the head, from a retrosternal goitre crowding the thoracic inlet. ## What is the first imaging test for a thyroid nodule? Ultrasound: size, solid or cystic, margins, calcifications and blood flow, and guidance for fine-needle aspiration. [Add to my cards (5)](https://durgical.app/estudiar/?add=/en/anatomy/thyroid-gland/) Educational information, not medical advice. For any symptom, see a health professional. ## Its names **Official Latin (TA2)** glandula thyreoidea TA2 3863 **Official Spanish (DeCS)** Glándula Tiroides DeCS D013961 **English (TA2)** Thyroid gland ## Related - [Parathyroid glands](https://durgical.com/en/anatomy/parathyroid-glands/) - [Recurrent laryngeal nerves](https://durgical.com/en/anatomy/recurrent-laryngeal-nerve/) - [Trachea](https://durgical.com/en/anatomy/trachea/) - [Cricoid cartilage](https://durgical.com/en/anatomy/cricoid-cartilage/) - [Superior thyroid artery](https://durgical.com/en/anatomy/superior-thyroid-artery/) - [Inferior thyroid artery](https://durgical.com/en/anatomy/inferior-thyroid-artery/) Sources: Terminologia Anatomica (TA2); [DeCS](https://decs.bvsalud.org/es/ths/resource/?id=14349); [Anatomy, Head and Neck, Thyroid](https://www.ncbi.nlm.nih.gov/books/NBK470452/); Tratado de anatomía humana (9.ª ed.), tomo II, Libro IV Angiología, sección 4: Venas (sistemas de las venas cavas superior e inferior, vena porta, venas del raquis). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/anatomy/thyroid-gland/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/thyroid-gland/