Hypothyroidism Versus Hyperthyroidism in Patients With Abnormal Uterine Bleeding: An Observational Study.

Introduction Abnormal uterine bleeding (AUB) is a common gynecological problem, and thyroid dysfunction is an important potentially reversible endocrine cause of menstrual abnormalities. Hypothyroidism and hyperthyroidism may produce different menstrual and clinical manifestations. The present study aimed to compare the clinical, menstrual, ultrasonographic, and laboratory characteristics of patients with hypothyroidism and hyperthyroidism presenting with AUB. Materials and methods A prospective observational study was conducted in the Department of Obstetrics and Gynaecology at Government RDBP Jaipuria Hospital, Jaipur, from January 2025 to December 2025 after Institutional Ethics Committee approval. A total of 252 women with AUB were enrolled using consecutive sampling. Participants underwent clinical, menstrual, ultrasonographic, and thyroid-function evaluation, with menstrual characteristics assessed at enrolment using a predesigned and structured questionnaire. Serum-free T3, free T4, and TSH were assessed using chemiluminescence immunoassay. Data were analyzed using IBM SPSS Statistics Version 26; categorical and continuous variables were compared using appropriate statistical tests, with p<0.05 considered significant. Results Among 252 women with AUB, hypothyroidism was identified in 33 (13.1%), while hyperthyroidism was present in eight (3.2%) women. Irregular menstruation was significantly more frequent among hyperthyroid patients (six (75.0%)) than hypothyroid patients (nine (27.3%), p=0.012), whereas menorrhagia was more frequent among hypothyroid patients (18 (54.5%)) than hyperthyroid patients (two (25.0%)). Lethargy and weight gain were observed in 22 (66.7%) and 15 (45.5%) hypothyroid patients, respectively, while weight loss occurred in eight (100.0%) hyperthyroid patients. Endometrial hyperplasia was observed in 15 (45.5%) hypothyroid and two (25.0%) hyperthyroid patients. Mean free T3, free T4, and thyroid-stimulating hormone (TSH) differed significantly between the groups (all p<0.001). Conclusion Hypothyroidism was more common than hyperthyroidism among women presenting with AUB and was predominantly associated with menorrhagia, whereas hyperthyroidism was more frequently associated with irregular menstruation and oligomenorrhoea. The contrasting clinical profiles support the importance of thyroid-function assessment in women presenting with AUB, particularly when characteristic menstrual or systemic features are present.