Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (843 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
A syndrome that results from abnormally low secretion of thyroid hormones from the thyroid gland, leading to a decrease in basal metabolic rate. In its most severe form, there is accumulation of mucopolysaccharides in the SKIN and edema, known as myxedema. It may be primary or secondary due to other pituitary disease, or hypothalamic dysfunction.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Hypothyroidisms; Thyroid-Stimulating Hormone Deficiency; Deficiency, Thyroid-Stimulating Hormone; Hormone Deficiency, Thyroid-Stimulating; Thyroid-Stimulating Hormone Deficiencies; Thyroid Stimulating Hormone Deficiency; TSH Deficiency; Deficiency, TSH.
Where it fits in the MeSH classification
- Broader topics
- Thyroid Diseases
- Narrower topics
- Congenital Hypothyroidism; Myxedema
- See also
- Congenital Hypothyroidism; Myxedema
Related concepts
- Thyroid Hormones
- Thyroid Gland
- Basal Metabolic Rate
- Mucopolysaccharides
- Edema
- Myxedema
Research landscape
PubMed indexes 37,285 records tagged with the MeSH heading “Hypothyroidism” (counts retrieved 2026-11-04). 4,583 of them (12.3%) were published from 2020 onward, and the busiest period so far is through 1999 with 20,544 records.
Reviews account for 3,954 records (10.6%) and meta-analyses for 326. Randomized controlled trials number 348 (0.9%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 20,544 |
| 2000-2009 | 5,533 |
| 2010-2019 | 6,625 |
| 2020 onward | 4,583 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 3,954 | 10.6% |
| Meta-analyses | 326 | 0.9% |
| Randomized controlled trials | 348 | 0.9% |
Method: PubMed query "Hypothyroidism"[MeSH Terms] with publication-type and date filters, retrieved 2026-11-04.
Reading the evidence in metabolism and endocrine disease
Studies of diabetes, obesity and hormone disorders often follow blood tests such as glucose, HbA1c or hormone levels, which are stand-ins for outcomes that matter more, such as complications. Lifestyle and diet research is largely observational, and weight and diabetes trials can differ in how long people were followed. Nothing on this page is advice about medicines, insulin or diet; talk to a qualified clinician about your own situation. Check whether the outcome was a lab value or a clinical event, and the type and duration of the condition studied.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| The Association between Depression, Anxiety, and Thyroid Disease: A UK Biobank Prospective Cohort Study | 2024 | Research article Design not recorded in structured metadata | 19 | cc by PMID 40226662 · DOI · PMC11918962 |
| Subtype-specific causal effects of hypothyroidism on obstructive sleep apnea: A bidirectional Mendelian randomization study | 2025 | Research article Design not recorded in structured metadata | 7 | cc by PMID 40629611 · DOI · PMC12237354 |
| Levothyroxine therapy in thyroidectomized patients: ongoing challenges and controversies | 2025 | Review article Design not recorded in structured metadata | 7 | cc by PMID 40491597 · DOI · PMC12146200 |
| Fasting vs Nonfasting, Dose-adjusted Levothyroxine Ingestion in Hypothyroidism: A Randomized Clinical Trial | 2026 | Randomized controlled trial Design not recorded in structured metadata | 2 | cc by PMID 41431302 · DOI · PMC13017094 |
The Association between Depression, Anxiety, and Thyroid Disease: A UK Biobank Prospective Cohort Study [1]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundThere is a lack of comprehensive data regarding the association of depression and anxiety for the subsequent risk of thyroid disease.
- Closing excerpt
- Therefore, any level of depression and anxiety should be taken into consideration in thyroid disease risk prediction and prevention.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (247 words)
BackgroundThere is a lack of comprehensive data regarding the association of depression and anxiety for the subsequent risk of thyroid disease.AimTo examine this prospective association between depression and anxiety and the risk of potential thyroid diseases, a large prospective study was conducted using data from UK Biobank.Materials and methodsDepression and anxiety were measured through self-reported Patient Health Questionnaire-4 (PHQ-4) at baseline, thyroid disease was diagnosed by corresponding hospital data documented through International Classification of Diseases (ICD)-10 codes. Cox proportional hazard models and restricted cubic splines were employed to analyze the associations.ResultsIn a 13-year follow-up cohort study involving 349,993 participants, 9,877 (2.82%) individuals developed thyroid disease. Significant associations were observed between depression, anxiety, and risk of both hypothyroidism and hyperthyroidism among all participants, the adjusted hazard ratios (HRs) for PHQ scores were as follows: mild 1.27 (95% CI, 1.20-1.36), moderate 1.33 (95% CI, 1.17-1.51), and severe 1.56 (95% CI, 1.31-1.85). For hyperthyroidism, the HRs were mild 1.19 (95% CI, 1.03-1.38), moderate 1.43 (95% CI, 1.08-1.90), and severe 1.84 (95% CI, 1.28-2.66). The adjusted HRs indicating the association between depression, anxiety, and hypothyroidism remained significant for both males and females. The relationship between PHQ score and the risk of thyroid disease shows linear in restricted cubic spline.ConclusionDepression and anxiety exposure is associated with subsequent risk of thyroid diseases, the more severe the depression and anxiety, the greater the associated risk. Therefore, any level of depression and anxiety should be taken into consideration in thyroid disease risk prediction and prevention.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 40226662 · DOI · PMC11918962
Subtype-specific causal effects of hypothyroidism on obstructive sleep apnea: A bidirectional Mendelian randomization study [2]
Abstract reading summary — source excerpts
- Opening excerpt
- This study investigates the subtype-specific causal relationships between hypothyroidism (HT) and obstructive sleep apnea (OSA) using a bidirectional Mendelian randomization (MR) design.
- Closing excerpt
- The findings highlight the need for personalized screening and management strategies for patients with different forms of thyroid dysfunction.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (176 words)
This study investigates the subtype-specific causal relationships between hypothyroidism (HT) and obstructive sleep apnea (OSA) using a bidirectional Mendelian randomization (MR) design. A two-sample MR analysis was conducted based on genome-wide association study summary statistics from European populations, including multiple HT subtypes and thyroid function indicators. The inverse variance weighted method was used as the primary analysis, supplemented by MR-Egger regression, weighted median, and leave-one-out analyses. Sensitivity analyses assessed pleiotropy and heterogeneity. Bidirectional MR was performed to explore causal directions between HT and OSA. Hypothyroidism, drug reimbursement, hypothyroidism, strict autoimmune, and congenital iodine deficiency syndrome/HT were significantly associated with an increased risk of OSA. Thyroglobulin exhibited a protective causal effect against OSA. In the reverse MR analysis, genetically predicted OSA was found to causally increase the risk of hypothyroidism, drug reimbursement. No substantial pleiotropy was detected, and the findings were robust across multiple analytical methods. This study revealed subtype-specific and bidirectional causal associations between HT and OSA. The findings highlight the need for personalized screening and management strategies for patients with different forms of thyroid dysfunction.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 40629611 · DOI · PMC12237354
Levothyroxine therapy in thyroidectomized patients: ongoing challenges and controversies [3]
Abstract reading summary — source excerpts
- Opening excerpt
- This mini-review provides an update on the challenges and controversies surrounding levothyroxine therapy in thyroidectomized patients, following an extensive review on dosing strategies and available formulations.
- Closing excerpt
- Despite ongoing research, the optimal management of thyroidectomized patients continues to be an open issue.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (152 words)
This mini-review provides an update on the challenges and controversies surrounding levothyroxine therapy in thyroidectomized patients, following an extensive review on dosing strategies and available formulations. Despite efforts to establish an ideal dosage adjustment method, achieving optimal thyroid hormone replacement remains complex due to interindividual variations in the hypothalamic-pituitary-thyroid axis and the pharmacokinetic and pharmacodynamic limitations of exogenous levothyroxine. Additionally, this review highlights the importance of evaluating the risk-benefit ratio of levothyroxine therapy, particularly in the setting of TSH suppression, focusing on its effects on quality of life, bone metabolism, and cardiac rhythm. Levothyroxine-induced subclinical hyperthyroidism may contribute to an increased risk of atrial fibrillation and alterations in bone mineral density, with implications that remain a subject of debate. Given the incomplete replication of endogenous thyroid hormone action by levothyroxine monotherapy, a tailored therapeutic approach is crucial. Despite ongoing research, the optimal management of thyroidectomized patients continues to be an open issue.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 40491597 · DOI · PMC12146200
Fasting vs Nonfasting, Dose-adjusted Levothyroxine Ingestion in Hypothyroidism: A Randomized Clinical Trial [4]
Abstract reading summary — source excerpts
- Opening excerpt
- IntroductionLevothyroxine (LT4) is recommended for intake in a fasting state to optimize absorption.
- Closing excerpt
- Given the strong patient preference, this patient-centered approach may offer a viable alternative to fasting administration.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (268 words)
IntroductionLevothyroxine (LT4) is recommended for intake in a fasting state to optimize absorption. However, fasting intake is often burdensome and may reduce adherence. In a previous questionnaire study, we observed a strong patient preference for taking LT4 with breakfast. Therefore, we conducted a randomized controlled trial to evaluate whether nonfasting LT4 intake-accompanied by a 15% dose increase-could maintain TSH stability compared to fasting LT4 intake.MethodsAdults with well-controlled hypothyroidism were randomized to fasting or dose-adjusted, breakfast LT4 intake. TSH, free T4, and total T3 were measured every 6 weeks, followed by LT4 dose adjustment if needed. The primary outcome was TSH stability, defined as 2 consecutive values within the reference range and a maximum ±1 mIU/L change from baseline. Patients were followed until TSH stability was reached, with a maximum of 24 weeks. After the initial study period, patients in the fasting group were invited to cross over to nonfasting intake, with similar follow-up.ResultsEighty-eight patients (80.7% female, median age 62y [interquartile range: 49-69]) were randomized to fasting (n = 43) or breakfast intake (n = 45). TSH stability was comparable between groups: 74.4% [95% confidence interval (CI): 61.0-88.0%] in the fasting vs 73.3% (95%CI: 60.0-87.0%) in the breakfast group (P = not significant). Similar findings were observed in the crossover group. The breakfast group reported greater improvement in self-reported well-being (33.3% vs 16.3%, P = .07) and a stronger preference for nonfasting intake (76.2% vs 44.2%, P ConclusionLT4 ingestion with breakfast with a 15% dose increase maintained TSH stability and improved patient well-being. Given the strong patient preference, this patient-centered approach may offer a viable alternative to fasting administration.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41431302 · DOI · PMC13017094
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Subclinical Hypothyroidism in Pregnancy: A Systematic Review and Meta-Analysis [5]
- Research article Association of maternal thyroid function with birthweight: a systematic review and individual-participant data meta-analysis [6]
- Research article Association of Thyroid Hormone Therapy With Quality of Life and Thyroid-Related Symptoms in Patients With Subclinical Hypothyroidism: A Systematic Review and Meta-analysis [7]
- Research article Subclinical Hypothyroidism and Type 2 Diabetes: A Systematic Review and Meta-Analysis [8]
- Research article Risk of hypothyroidism following hemithyroidectomy: systematic review and meta-analysis of prognostic studies [9]
- Research article Association between maternal thyroid function and risk of gestational hypertension and pre-eclampsia: a systematic review and individual-participant data meta-analysis [10]
Full-text reviews on EvidenceLib
Open-access review articles about this topic, reproduced in full with authors, licence and references.
Prevalence of hyperthyroidism, hypothyroidism, and euthyroidism in thyroid eye disease: a systematic review of the literature
Juliana Muñoz-Ortiz, Maria Camila Sierra-Cote, Estefanía Zapata-Bravo et al. · Systematic Reviews 2020 · CC BY 4.0
Association between subclinical hypothyroidism and depression: an updated systematic review and meta-analysis
Huai Heng Loh, Lee Ling Lim, Anne Yee et al. · BMC Psychiatry 2019 · CC BY 4.0
References
- Fan T, Luo X, Li X, Shen Y, Zhou J. The Association between Depression, Anxiety, and Thyroid Disease: A UK Biobank Prospective Cohort Study. . 2024. PMID 40226662 · DOI · PMC11918962
- Zhang H, Wu Z, Chen Q, Yu G, Chen L, Ma Y, et al.. Subtype-specific causal effects of hypothyroidism on obstructive sleep apnea: A bidirectional Mendelian randomization study. . 2025. PMID 40629611 · DOI · PMC12237354
- Rossi L, Paternoster M, Cammarata M, Bakkar S, Miccoli P. Levothyroxine therapy in thyroidectomized patients: ongoing challenges and controversies. . 2025. PMID 40491597 · DOI · PMC12146200
- Willems JIA, van Twist DJL, Helmich F, Sluiter T, Medici M, Peeters RP, et al.. Fasting vs Nonfasting, Dose-adjusted Levothyroxine Ingestion in Hypothyroidism: A Randomized Clinical Trial. . 2026. PMID 41431302 · DOI · PMC13017094
- Maraka S, Ospina NM, O'Keeffe DT, Espinosa De Ycaza AE, Gionfriddo MR, Erwin PJ, et al.. Subclinical Hypothyroidism in Pregnancy: A Systematic Review and Meta-Analysis. Thyroid. 2016. PMID 26837268 · DOI · PMC4827301
- Derakhshan A, Peeters RP, Taylor PN, Bliddal S, Carty DM, Meems M, et al.. Association of maternal thyroid function with birthweight: a systematic review and individual-participant data meta-analysis. Lancet Diabetes Endocrinol. 2020. PMID 32445737 · DOI · PMC8168324
- Feller M, Snel M, Moutzouri E, Bauer DC, de Montmollin M, Aujesky D, et al.. Association of Thyroid Hormone Therapy With Quality of Life and Thyroid-Related Symptoms in Patients With Subclinical Hypothyroidism: A Systematic Review and Meta-analysis. JAMA. 2018. PMID 30285179 · DOI · PMC6233842
- Han C, He X, Xia X, Li Y, Shi X, Shan Z, et al.. Subclinical Hypothyroidism and Type 2 Diabetes: A Systematic Review and Meta-Analysis. PLoS One. 2015. PMID 26270348 · DOI · PMC4535849
- Verloop H, Louwerens M, Schoones JW, Kievit J, Smit JW, Dekkers OM. Risk of hypothyroidism following hemithyroidectomy: systematic review and meta-analysis of prognostic studies. J Clin Endocrinol Metab. 2012. PMID 22511795 · DOI
- Toloza FJK, Derakhshan A, Männistö T, Bliddal S, Popova PV, Carty DM, et al.. Association between maternal thyroid function and risk of gestational hypertension and pre-eclampsia: a systematic review and individual-participant data meta-analysis. Lancet Diabetes Endocrinol. 2022. PMID 35255260 · DOI · PMC10314731
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-11-04; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-11-04.
See how EvidenceLib is built. Spotted an error? Email support@evidencehelix.com.
Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.