The INMSG Survey on the Loss of Signal Management on the First Side During Planned Bilateral Thyroid Surgery.

BACKGROUND: The aim of this study is to describe the management and associated follow-up strategies adopted by thyroid surgeons with different surgical volumes when loss of signal (LOS) occurred on the first side of planned bilateral thyroid surgery, and to further define the consensus on intraoperative neuromonitoring (IONM) applications. METHODS: The International Neural Monitoring Study Group (INMSG) web-based survey was sent to 950 thyroid surgeons worldwide. The survey included information on the participants, IONM team/equipment/procedure, intraoperative/postoperative management of LOS, and management of LOS on the first side of thyroidectomy for benign and malignant disease. RESULTS: Out of 950, 318 (33.5%) respondents completed the survey. Subgroup analyses were performed based on thyroid surgery volume: <50 cases/year (n = 108, 34%); 50 to 100 cases/year (n = 69, 22%); and >100 cases/year (n = 141, 44.3%). High-volume surgeons were significantly (P < .05) more likely to perform the standard procedures (L1-V1-R1-S1-S2-R2-V2-L2), to differentiate true/false LOS, and to verify the LOS lesion/injury type. When LOS occurs, most surgeons arrange otolaryngologists or speech consultation. When first-side LOS occurs, not all respondents decided to perform stage contralateral surgery, especially for malignant patients with severe disease (eg, extrathyroid invasion and poorly differentiated thyroid cancer). CONCLUSIONS: Respondents felt that IONM was optimized when conducted under a collaborative team-based approach, and completed IONM standard procedures and management algorithm for LOS, especially those with high volume. In cases of first-site LOS, surgeons can determine the optimal management of disease-related, patient-related, and surgical factors. Surgeons need additional education on LOS management standards and guidelines to master their decision-making process involving the application of IONM.

Factors predicting the use of the backward upward rightward pressure maneuver in thyroid surgery: a single-center retrospective cohort study.

BACKGROUND: The purpose of this study was to evaluate the predictability of utilizing the backward upward rightward pressure (BURP) maneuver and the efficacy of related tests in patients with a challenging airway and a Mallampati score of 2 or higher who underwent scheduled elective thyroid surgery. METHODS: Patient files were scanned for 300 adult patients who had undergone thyroid surgery under general anesthesia. The information included their medical history of thyroid disease, previous thyroid surgery, and evaluation tests for difficult intubation such as Mallampati score, maximum mouth opening, ease of intubation, thyroid goitre grade, and whether the BURP maneuver was performed. Patients who had a history of difficult intubation or a Cormack Lehane score less than 2 were excluded. Additionally, the patients were divided into two groups: one group underwent the BURP maneuver (n = 78) and the other did not (n = 56). RESULTS: Statistically significant differences in the maximum mouth openings and thyroid goitre grade were observed between the groups according to the preoperative evaluation. Furthermore, significant differences were noted between the groups in terms of the ease of intubation, intubation time, Cormack-Lehane score, and number of intubation attempts. CONCLUSION: There may be a correlation between the maximum mouth opening and thyroid goitre grade in predicting the use of the BURP maneuver. It is important to keep in mind, however, that difficult intubation may occur in some uncommon types of goiter, such as retrosternal goiter, even if the thyroid gland size is small. Therefore, it may be useful to consider performing the BURP maneuver.

Cogent integration of inflammatory biomarkers and perioperative complications of thyroid surgery in thyroidology.

OBJECTIVE: Back to the sources, postoperative nausea and vomiting, hypo- and hypertension, heart rate alterations, and hypoxemia due to laryngospasm might be considered perioperative complications. METHODS: This cross-sectional study was conducted at an Education and Research Hospital between January 2018 and June 2023. The study included a total of 437 cases of thyroid surgery. The demographic data such as age, sex, co-morbidities of the instances, hypotension, hypertension, bradycardia, hypoxemia, and postoperative nausea and vomiting, as well as laboratory data were obtained and analyzed. RESULTS: Of 437 cases, 334 (76%) were females and 103 (24%) were males, with a mean age of 51.83±11.91 years and 55.32±11.87 years, respectively. No statistical significance was realized between the complications, co-morbid diseases, and age. Notably, no liaison between the complications after awakening from the anesthesia and preoperative laboratory parameters was discerned. However, a high but no significant relationship was revealed between the platelet-to-lymphocyte ratio (P/L) in cases with hypoxemia and hypotension. Finally, no significance between laboratory values, bradycardia, hypertension, and postoperative nausea and vomiting was distinguished. CONCLUSION: We postulate that the so-called inflammatory biomarkers measured at the time of preoperative examination in the blood count concept selectively do not enrich for anticipating complications that arise in the perioperative echelon.

Associations between thyroid function, thyroid diseases, and primary aldosteronism.

OBJECTIVE: Previous studies focusing on primary aldosteronism (PA) and thyroid diseases were controversial. Hence, this study aimed to examine associations between thyroid function, thyroid diseases, and PA and its subtypes. DESIGN AND METHODS: This was a cross-sectional study, which enrolled 1023 patients with PA and 6138 patients with essential hypertension (EH) admitted to Hypertension Center of People's Hospital of Xinjiang Uygur Autonomous Region from August 2011 to June 2022. All patients with PA were accurately classified into aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA) by adrenal vein sampling (AVS). Multivariate logistic regression analysis was used to assess the relationship of thyroid function, thyroid nodules, and PA and its subtypes. RESULTS: A total of 7161 patients (327 APA and 696 IHA, and 6138 EH) were included with a mean age of 48.20 ± 8.83 years. PA patients and PA subtypes showed lower FT4, FT3, TT4, TT3, and prevalence of positive TPOAb, meanwhile higher prevalence of thyroid nodules than EH patients (PA: 56.10%, IHA: 56.90%, APA: 54.80%, and EH: 48.90%, respectively). PA (adjusted OR: 1.290, 95% CI: 1.035-1.607, P = .02) and its subtype (IHA) (adjusted OR: 1.316, 95% CI: 1.005-1.724, P = .04) were significantly associated with thyroid nodules. Compared to patients with lower plasma aldosterone concentration (PAC) levels (<12 ng/dL), patients with PAC levels ≥ 12 ng/dL presented a higher prevalence of thyroid nodules. CONCLUSIONS: PA patients had lower thyroid function and higher prevalence of thyroid nodules compared to EH patients. Therefore, the screening of thyroid function and thyroid nodules may be indispensable for PA patients.

Thyroid Diseases After Total Knee Replacement: A Multi-center, Propensity-score-matched Cohort Study.

BACKGROUND/AIM: Thyroid diseases are prevalent endocrine disorders that significantly affect overall health. Although the impact of pre-existing thyroid dysfunction on total knee replacement (TKR) outcomes has been studied, the potential for TKR to increase the risk of developing thyroid disorders remains unexplored. PATIENTS AND METHODS: We examined electronic medical records from a large U.S. research network in the TriNetX research network. The study focused on patients with osteoarthritis, comparing those who had total knee replacement surgery (TKR) between 2005 and 2018 to a non-TKR group who did not have the surgery. Propensity score matching was employed to control for critical confounders. The hazard ratios (HRs) for the risk of thyroid diseases in TKR patients versus non-TKR controls were assessed. RESULTS: Post-matching, the TKR cohort demonstrated a significantly higher risk of developing thyroid diseases compared to the non-TKR cohort (unadjusted HR=1.218, 95%CI=1.169-1.269). This elevated risk persisted after adjusting for confounders (adjusted HR=1.126, 95%CI=1.061-1.196). Stratification analysis indicated that female TKR patients and those aged ≥65 years were at higher risk of developing thyroid diseases than their respective control groups. CONCLUSION: This study suggests a potential link between TKR and an increased risk of thyroid diseases, particularly among older adults and females. Potential mechanisms include inflammatory processes, surgical stress, autoimmune responses, and pharmacological effects. Healthcare providers should be vigilant in monitoring and managing thyroid dysfunction in TKR patients. Further research is necessary to elucidate the underlying mechanisms and develop preventive strategies.

The Role of Nutrition on Thyroid Function.

Thyroid function is closely linked to nutrition through the diet-gut-thyroid axis. This narrative review highlights the influence of nutritional components and micronutrients on thyroid development and function, as well as on the gut microbiota. Micronutrients such as iodine, selenium, iron, zinc, copper, magnesium, vitamin A, and vitamin B12 influence thyroid hormone synthesis and regulation throughout life. Dietary changes can alter the gut microbiota, leading not just to dysbiosis and micronutrient deficiency but also to changes in thyroid function through immunological regulation, nutrient absorption, and epigenetic changes. Nutritional imbalance can lead to thyroid dysfunction and/or disorders, such as hypothyroidism and hyperthyroidism, and possibly contribute to autoimmune thyroid diseases and thyroid cancer, yet controversial issues. Understanding these relationships is important to rationalize a balanced diet rich in essential micronutrients for maintaining thyroid health and preventing thyroid-related diseases. The synthetic comprehensive overview of current knowledge shows the importance of micronutrients and gut microbiota for thyroid function and uncovers potential gaps that require further investigation.

Thyroid dysfunction in the wake of Omicron: understanding its role in COVID-19 severity and mortality.

Purpose: SARS-CoV-2 can invade the thyroid gland. This study was to delineate the risk of thyroid dysfunction amidst the prevalence of the Omicron variant, and to investigate the correlation between thyroid function and Coronavirus disease 2019 (COVID-19) outcomes. The study also aimed to ascertain whether thyroid dysfunction persisted during COVID-19 recovery phase. Methods: This was a retrospective cohort study. COVID-19 patients from the Renmin Hospital of Wuhan University, China during the epidemic of Omicron variants were included, and their thyroid function were analyzed in groups. Results: A history of thyroid disease was not associated with COVID-19 outcomes. COVID-19 can lead to a bimodal distribution of thyroid dysfunction. The severity of COVID-19 was inversely proportional to the levels of thyroid- stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxine (FT4), leading to a higher prevalence of thyroid dysfunction. Severe COVID-19 was a risk factor for euthyroid sick syndrome (ESS) (OR=22.5, 95% CI, 12.1 - 45.6). Neutrophil to lymphocyte ratio mediated the association between severe COVID-19 and ESS (mediation effect ratio = 41.3%, p < 0.001). ESS and decreased indicators of thyroid function were associated with COVID-19 mortality, while high levels of FT3 and FT4 exhibited a protective effect against death. This effect was more significant in women (p < 0.05). During the recovery period, hyperthyroidism was quite uncommon, while a small percentage of individuals (7.7%) continued to exhibit hypothyroidism. Conclusion: COVID-19 severity was linked to thyroid dysfunction. Severe COVID-19 increased the risk of ESS, which was associated with COVID-19 mortality. Post-recovery, hyperthyroidism was rare, but some individuals continued to have hypothyroidism.

Determining the frequency of thyroid involvement in chest CT scans of COVID-19 patients and its correlation with the severity of lung involvement and survival of patients in 2020.

Introduction: This study aimed to determine the frequency of thyroid gland involvement in chest CT scans of patients with COVID-19 admitted to university-affiliated hospitals and assess its relationship with the severity of lung involvement and patient survival in 2020. Material and methods: In this retrospective cross-sectional study, 1000 PCR-positive patients with COVID-19 who were referred to University-affiliated Hospital in 2020 and had chest CT performed within 72 hours of admission to the hospital were examined. The data was collected by patient file information and CT findings recorded in the PACS system, including thyroid involvement, the severity of lung involvement, and findings related to the death and recovery of patients. Results: The mean age of the examined patients was 56 years. 525 people (52.5%) were men, and 475 (47.5%) were women. 14% had severe pulmonary involvement, and 9.3% had very severe involvement. Moreover, 15.9 percent of them had deceased. 19.7% had focal thyroid involvement, 14% had diffuse involvement, and 66.3% were healthy subjects. Male gender and older age showed a significant relationship with thyroid gland involvement. The severity of lung involvement, the death rate in patients, and hospitalization in ICU were also significantly related to thyroid gland involvement in patients with COVID. Discussion and conclusion: This study highlights the importance of considering thyroid-gland involvement in the comprehensive management of COVID-19 patients. Routine screening and monitoring of thyroid-function may facilitate earlier detection and appropriate management of thyroid-related complications, potentially improving clinical outcomes. This study suggests that in COVID-19 infection the monitoring of thyroid function is prudent, particularly in cases of more serious disease.

Paediatric thyroid disease.

The spectrum of thyroid disorders presenting to paediatricians is different to that seen by adult physicians. Referrals reflect cases detected by the neonatal screening programme for congenital hypothyroidism and many of the inherited defects of thyroid hormone generation or action will be manifest in early life. Autoimmune thyroid disease can be particularly challenging to manage in the young and the potential impact of thyroid status on neurodevelopment and schooling are key considerations throughout childhood and adolescence.

Bridging the Gap: A Qualitative Assessment of General Surgery Resident Confidence and Knowledge Deficits in Managing Surgical Endocrinopathy.

BACKGROUND: Most thyroid and parathyroid surgeries are performed by nonfellowship trained, low-volume surgeons with associated higher complication rates. Furthermore, the average number of endocrine procedures performed by general surgery residents is decreasing. While previous studies have documented a lack of general surgery resident confidence in performing these procedures, the specific knowledge gaps in endocrine surgery remain unexplored. METHODS: We conducted semi-structured interviews with surgical residents (clinical PGY3-PGY5) at a high-volume academic center with an endocrine surgery fellowship to discuss their experience, knowledge, and deficits managing patients with surgical thyroid and parathyroid disease. Interviews were audio-recorded, de-identified, and transcribed verbatim. Content analysis was used to identify areas of confidence and knowledge deficits in all phases of care. RESULTS: Overall, 14 trainees participated in the study (50% women, mean PGY: 3.8). Preoperatively, residents were confident with thyroid nodule and primary hyperparathyroidism work-up, but less comfortable with rare conditions. Residents were uncomfortable using ultrasound to identify suspicious lymph nodes or abnormal parathyroid glands. Residents perceived knowledge deficits in the multidisciplinary care and work-up of patients with advanced thyroid cancer. Intraoperatively, most residents were confident performing thyroidectomy and focused parathyroidectomy, but less comfortable performing 4-gland explorations or neck dissections. Several had concern with independently identifying and protecting the recurrent laryngeal nerve or locating parathyroid glands in the setting of negative localization. Residents noted a lack of autonomy in both thyroidectomy and parathyroidectomy. Postoperatively, residents felt confident in the acute management of patients, but identified deficits in long-term management of patients with thyroid cancer or chronic complications. CONCLUSIONS: Despite confidence in managing "bread and butter" cervical endocrine surgery in all phases of care, residents perceive a lack of meaningful autonomy intraoperatively. Further educational endeavors may be required to ensure graduating residents are "practice ready" for straightforward cases they may encounter in practice as a general surgeon. A lack of exposure to complex endocrinopathy even at a high-volume center suggests that comprehensive endocrine surgery fellowship remains critical.

Thyroid dysfunction caused by immune checkpoint inhibitors improves cancer outcomes.

A common immune-related adverse event (irAE) with immune checkpoint inhibitors (ICIs) is thyroid dysfunction (TD-irAEs). The clinical presentation can be varied, and its association with prognosis remains unclear. We investigated the characteristics of TD-irAEs and their association with clinical outcomes among cancer patients treated with ICIs in a real-life setting. Response to treatment was assessed using RECIST v1.1. We calculated the probability of recurrence and survival associated with TD-irAEs using multivariable-adjusted regression and Cox proportional hazards models. In this single-center retrospective analysis, we included 238 patients (72% male) with a median age of 69.5 years. Primary tumors were melanoma (23.1%), lung (60.5%), or urothelial cancer (16.4%), treated with atezolizumab (23.1%), pembrolizumab (44.5%), ipilimumab (0.4%), and/or nivolumab (25.6%). Seventy (29%) patients developed TD-irAEs in a median time of 69 days (41-181). The incidence of TD-irAEs with combination therapy was higher than with monotherapy (67% vs 6.3%, P = 0.011). TD-irAE patients showed a higher objective response rate (ORR) than those without TD-irAEs (60% vs 42.3%, P = 0.013) and longer overall survival (OS) 45 vs 16 months, P < 0.006. Patients who developed TD-irAEs had a relative reduction of 77% (OR 0.23, 95% CI 0.11-0.47) in the risk of progression and of 47% in the risk of mortality (HR 0.53, 95% CI 0.36-0.80), independent of age, sex, primary tumor, or ICI regimen. TD-irAEs occur in nearly 30% of our patients receiving ICIs. In our analysis, TD-irAEs appeared to be associated with higher ORR and longer OS and showed a reduction in the risk of progression and mortality.

Association Between Subclinical Thyroid Dysfunction and Cognitive Decline: Findings From the ELSA-Brasil Study.

BACKGROUND: Thyroid dysfunction has been associated with cognitive decline and dementia. However, the role of subtle thyroid hormone alterations in cognitive function is still debatable. METHODS: Participants without overt thyroid dysfunction aged 35-74 years at baseline were evaluated in 3 study waves (2008-2010, 2012-2014, and 2017-2019). We assessed baseline thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3). Cognitive performance was evaluated every 4 years in each wave using 10-word immediate and late recall, word recognition, semantic (animals category) and phonemic (letter f) verbal fluency, and the trail-making B-version tests. A global composite z-score was derived from these tests. The associations of TSH, FT4, and FT3 levels with cognitive decline over time were evaluated using linear mixed-effect models adjusted for sociodemographic, clinical, and lifestyle variables. RESULTS: In 9 524 participants (mean age 51.2 ±â€…8.9 years old, 51% women, 52% White), there was no association between baseline TSH, FT4, and FT3 levels and cognitive decline during the follow-up. However, increase in FT4 levels over time was associated with faster memory (ß = -0.004, 95% CI = -0.007; -0.001, p = .014), verbal fluency (ß = -0.003, 95% CI = -0.007; -0.0005, p = .021), executive function (ß = -0.004, 95% CI = -0.011; -0.003, p < .001), and global cognition decline (ß = -0.003, 95% CI = -0.006; -0.001, p = .001). Decrease in FT4 levels over time was associated with faster verbal fluency (ß = -0.003, 95% CI = -0.007; -0.0004, p = .025) and executive function (ß = -0.004, 95% CI = -0.007; -0.0003, p = .031) decline. CONCLUSIONS: An increase or decrease in FT4 levels over time was associated with faster cognitive decline in middle-aged and older adults without overt thyroid dysfunction during 8 years of follow-up.

Thyroid Disorders.

This article includes a review of information primary care physicians need to know direct their evaluation and treatment of thyroid disorders that include sick euthyroid, hyperthyroidism, hypothyroidism, and subclinical thyroid disorders.

Bidirectional Association between Periodontitis and Thyroid Disease: A Scoping Review.

Periodontitis is a chronic inflammatory disease of the tissues surrounding and supporting the teeth. Due to the development of chronic inflammation, periodontitis can contribute to the development of several systemic diseases, including thyroid disease. Thyroid pathology includes benign, malignant, and autoimmune conditions leading to hypothyroidism, hyperthyroidism, or euthyroidism. Alterations in thyroid hormones, especially hypothyroidism, can reveal significant oral manifestations, including periodontitis. This scoping review aims to explore the probable causal relationship between periodontitis and thyroid disease, in terms of epidemiology, pathogenesis, and treatment. The search strategy follows the PRISMA-ScR guidelines. PubMed, Scopus, Web of Science, and Cochrane were searched from January 2014 to January 2024, entering the MESH terms "periodontitis" and "thyroid". Of 153 initial records, 20 articles were selected and discussed. There is a high prevalence of periodontitis among patients with thyroid disease, including thyroid cancer. The causes at the basis of this association are genetic factors, the oral microbiome, and proinflammatory cytokines. Periodontal treatment, specifically scaling and root planning, can ameliorate thyroid parameters. Although there are a few randomized controlled studies in the literature, this review lays the foundation for a bidirectional relationship between periodontitis and thyroid disease, the link to which is, once again, systemic inflammation.

No causal associations of genetically predicted birth weight and life course BMI with thyroid function and diseases.

OBJECTIVE: Observational studies have suggested associations of birth weight, childhood BMI, and adulthood BMI with thyroid function or diseases. However, the causal relationships remain unclear due to residual confounding inherent in conventional epidemiological studies. METHODS: We performed a two-sample Mendelian randomization (MR) study to investigate causal relationships of genetically predicted birth weight, childhood BMI, and adulthood BMI with a range of clinically relevant thyroid outcomes. Additionally, we conducted a reverse MR analysis on adulthood BMI. Data on exposures and outcomes were obtained from large-scale genome-wide association study meta-analyses predominantly composed of individuals of European ancestry. RESULTS: The MR analysis revealed no evidence of causal associations of birth weight or BMI at different life stages with thyrotropin (TSH) levels, hypothyroidism, hyperthyroidism, autoimmune thyroid disorders, or thyroid cancer. Contrarily, thyroid cancer demonstrated a significant causal relationship with increased adulthood BMI (ß = 0.010, 95% CI: 0.006-0.015; p = 5.21 × 10-6). CONCLUSIONS: Our comprehensive MR did not find causal links of birth weight, childhood BMI, or adulthood BMI with thyroid diseases but provided evidence that thyroid cancer may play a role in weight gain. Our research findings offer valuable insights into the intricate relationship between body weight and thyroid health throughout an individual's life.

The prevalence and determinants of diabetes mellitus and thyroid disorder comorbidity in Tabari cohort population.

Studies have shown that the co-occurrence of diabetes mellitus (DM) and thyroid dysfunction (TD) exacerbates diabetes complications and imposes a financial burden on the healthcare system. Therefore, this study aimed to investigate the prevalence of TD-DM comorbidity and its associated risk factors. This cross-sectional study was conducted on enrollment phase data of the TABARI cohort population which consisted of 10,255 adults aged between 35 to 70 years old residing in Sari, Mazandaran, Iran from 2015 to 2017. A total of 9939 out of 10,255 individuals (96.92%) entered the study. The prevalence of TD among T2DM patients was 13.2%. The prevalence of T2DM among patients with TD was 9.2%. Furthermore, the prevalence of TD-DM comorbidity in the overall population was 2.2%. Logistic regression analysis revealed that the odds of TD-DM comorbidity was significantly higher in women (OR 2.85; 95% CI 1.58-5.11), in the age group of 60-70 years (OR 9.62; 95% CI 3.69-25.10), in smokers (OR 2.32; 95% CI 1.19-4.52), in individuals with high waist circumference (WC) (OR 2.22; 95% CI 1.32-3.75), in individuals with low high-density lipoprotein (HDL) (OR 1.60; 95% CI 1.20-2.14), in individuals with high total cholesterol (TC) (OR 1.71; 95% CI 1.21-2.41), in individuals with high triglycerides (TG) (OR 1.79; 95% CI 1.27-2.51), and significantly lower in individuals with higher physical activity (PA) (OR 0.67; 95% CI 0.49-0.93). The present study demonstrated a prevalence of 2.2% in patients with both TD and T2DM. Additionally, female gender, older age, smoking, high WC, low HDL, high TC, high TG, and low PA were predictors of TD-DM comorbidity.

[Efficacy of prevention of recurrent laryngeal nerve injury in thyroid surgery]. / Effektivnost' profilaktiki povrezhdenii vozvratnogo gortannogo nerva pri operatsiyakh na shchitovidnoi zheleze.

OBJECTIVE: To evaluate the effectiveness of prevention of recurrent laryngeal nerve injury depending on thyroid gland lesion and extent of surgery. MATERIAL AND METHODS: There were 2412 thyroid surgeries between 2000 and 2020. Patients were divided into the main group (1689 patients) and the control group (729 patients). Patients with nodular thyroid gland lesions prevailed in both groups (987 (58.4%) and 415 (56.9%), respectively). All ones underwent atraumatic extrafascial desection and thyroid resection (ultrasonic scalpel). RESULTS. T: He upper laryngeal nerve injury occurred in 35 cases (1.4%). The number of surgeries with thyroid remnant preservation was significantly lower in the main group. The number of procedures with subtotal thyroid resection and thyroidectomy increased by 2.4 times (from 414 to 1010 operations, p<0.05). CONCLUSION: Improvement of surgical treatment of thyroid gland lesions consisting in new operative technique of recurrent laryngeal nerve isolation using ultrasonic scalpel reduces the incidence of recurrent laryngeal nerve injury from 2.3% to 1%. At the same time, the number of extended procedures in the main group significantly exceeded that in the control group (by 2.5 times).

The impact of environmental factors and contaminants on thyroid function and disease from fetal to adult life: current evidence and future directions.

The thyroid gland regulates most of the physiological processes. Environmental factors, including climate change, pollution, nutritional changes, and exposure to chemicals, have been recognized to impact thyroid function and health. Thyroid disorders and cancer have increased in the last decade, the latter increasing by 1.1% annually, suggesting that environmental contaminants must play a role. This narrative review explores current knowledge on the relationships among environmental factors and thyroid gland anatomy and function, reporting recent data, mechanisms, and gaps through which environmental factors act. Global warming changes thyroid function, and living in both iodine-poor areas and volcanic regions can represent a threat to thyroid function and can favor cancers because of low iodine intake and exposure to heavy metals and radon. Areas with high nitrate and nitrite concentrations in water and soil also negatively affect thyroid function. Air pollution, particularly particulate matter in outdoor air, can worsen thyroid function and can be carcinogenic. Environmental exposure to endocrine-disrupting chemicals can alter thyroid function in many ways, as some chemicals can mimic and/or disrupt thyroid hormone synthesis, release, and action on target tissues, such as bisphenols, phthalates, perchlorate, and per- and poly-fluoroalkyl substances. When discussing diet and nutrition, there is recent evidence of microbiome-associated changes, and an elevated consumption of animal fat would be associated with an increased production of thyroid autoantibodies. There is some evidence of negative effects of microplastics. Finally, infectious diseases can significantly affect thyroid function; recently, lessons have been learned from the SARS-CoV-2 pandemic. Understanding how environmental factors and contaminants influence thyroid function is crucial for developing preventive strategies and policies to guarantee appropriate development and healthy metabolism in the new generations and for preventing thyroid disease and cancer in adults and the elderly. However, there are many gaps in understanding that warrant further research.