The thyroid gland normally lies just caudal to the thyroid cartilage in the anterior neck. This location allows an examiner to inspect and palpate this bilobed structure, which in the adult human being weighs from 15 to 25 g. Physical examination of the thyroid gland enables the experienced clinician to construct a rather narrow differential of its anatomical pathology, whereas diagnostic testing is frequently necessary to establish the thyroid's functional status.
The patient should hold a glass of water and be seated. There should be room for the examiner on all sides of the seated patient. Place the patient's head in slight hyperextension with good crosslight falling on the anterior neck and then ask the patient to swallow. The outline of the thyroid gland in thin individuals can be observed frequently as a protuberance on both sides of the trachea moving cephalad in tandem with but 2 cm below the crest of the thyroid cartilage Look for abnormal enlargement, contour, asymmetry, and masses while the patient swallows repeatedly. The neck should also be inspected for abnormal masses and prominent pulsations. The deep structures of the anterior neck. These anatomic landmarks properly orient the examiner.
The art of thyroid gland palpation has spawned a number of distinct attitudes, and each examiner should, through practice, adopt a comfortable technique. Frequently it is advantageous to examine the gland while you stand behind as well as on each side of the patient. Identify the thyroid cartilage, the thyrocricoid membrane, and the cricoid cartilage, a horizontal structure 5 mm wide that marks the superior border of the isthmus. Palpate the isthmus (frequently impalpable unless enlarged), and if standing to the side of the patient, slide the tips of your fingers so that their palmar surfaces rest on the trachea with the dorsal surface medial to the sternocleidomastoid muscle. A frequent mistake is to move the fingers too laterally and trap the body of the muscle between your fingers and the trachea. The ipsilateral lobe can be palpated simultaneously with your thumb or with the other hand from the opposite direction. When you stand behind the patient, identify the landmarks and isthmus with one hand, and when in position to feel the thyroid lobe on that side, place the fingers of your other hand symmetrically on the other side of the trachea. Again identify each lobe while the patient swallows. Feel the gland's surface, note any asymmetry, texture, and estimate the size of each lobe (normally 7 to 10 g). When goiter is present, measure any discrete masses as well as the neck's greatest circumference. A penciled tracing of the goiter's outline provides a reliable record for future comparison. One should also palpate the neck for lymphadenopathy and search for masses (especially in the midline for abnormalities of the thyroglossal duct) and surgical scars.