Thyrotoxic hypokalemic periodic paralysis (THPP) is a rare but potentially fatal complication of thyrotoxicosis, characterized by transient episodes of muscle weakness in the setting of hypokalemia and underlying hyperthyroidism. Although thyrotoxicosis is more common in females, THPP predominantly affects males, especially in Asian populations, in which its prevalence is notably higher. Early recognition is essential to prevent serious complications such as cardiac arrhythmias and respiratory failure; however, THPP is frequently misdiagnosed, particularly in Western countries, due to clinical overlap with familial hypokalemic periodic paralysis. The pathophysiology of THPP involves thyroid hormone–induced upregulation of Na+/K+-ATPasease and heightened β-adrenergic sensitivity, which promote intracellular potassium shifts. Postprandial insulin surges following high carbohydrate intake further exacerbate this effect. Genetic susceptibility, including human leukocyte antigen haplotypes and mutations in ion channel genes (e.g., KCNE3, CACNA1S, SCN4A, and KCNJ18), plays a critical role. The resulting hypokalemia leads to hyperpolarization of muscle membranes, impairing excitability and causing paralysis. Structural muscle changes, such as sarcoplasmic reticulum proliferation and sodium channel dysfunction, may also contribute to THPP. Electrolyte abnormalities, including hypophosphatemia, hypomagnesemia, and hypocalcemia, are common due to transcellular shifts. This review underscores the importance of understanding the hormonal, genetic, and cellular mechanisms underlying THPP to enhance diagnostic accuracy and guide effective treatment strategies.

Introduction: C-reactive protein (CRP), urea, albumin, CRP/albumin ratio (CAR) and urea/albumin ratio (UAR) could be valuable biomarkers for determining the severity of illness in patients with COVID-19. This study aimed to determine the association between these markers and disease severity in COVID-19 patients on admission and days five to seven after admission. Methods: This retrospective study includes 153 adult COVID-19 patients admitted to Hospital Raja Perempuan Zainab II and Hospital Ampang from January 2021 to December 2021. Patients’ serum CRP, urea, albumin and creatinine levels were recorded on admission and on days five to seven after admission. The patients were categorised based on the Annex 2e guidelines published by the Ministry of Health, Malaysia and further classified as mild to moderate disease (stages 1-3) and severe to critical illness (stages 4-5). Results: On admission, urea, creatinine, CRP, UAR and CAR were significantly higher in the severe to critical group (p<0.001). The optimal cut-off value for the UAR was 0.16; the area under the curve (AUC) was 0.760, and sensitivity and specificity were 63.6% and 85.7%, respectively. The AUC of the CAR was 0.752, with 54.2% sensitivity and 91.4% specificity at an optimal cut-off value of 1.63. In severe to critical COVID-19 patients, albumin levels decreased significantly on days five to seven after admission, while urea levels remained significantly higher in this group (p<0.001, p<0.05, respectively). Conclusion: CRP, urea, albumin, CAR and UAR are promising biomarkers for predicting the severity of disease in COVID-19 patients.