Incidence, prevalence and risk factors for post-surgical hypocalcaemia and hypoparathyroidism

Hypocalcaemia following thyroid surgery is common and is associated with significant short and long term morbidity. Damage to or devascularisation of parathyroid glands is the predominant underlying mechanism; although other factors such as hungry bone syndrome may occasionally contribute to it in the immediate post-operative period. The reported incidence of post-surgical hypocalcaemia and/or hypoparathyroidism (PoSH) varies significantly in the literature; the variation thought to be at least partly due to differences in the definitions used. Figures on the prevalence of chronic or long term post-surgical hypocalcaemia in the population are unclear. Risk factors for PoSH have been extensively studied in recent years and may be classified into patient, disease and surgery related factors. Some risk factors are modifiable; but both modifiable and non-modifiable factors help in generating a risk profile that may be used to select patients for preventative measures and/or changes in surgical strategy. This narrative review discusses recent literature on the incidence, prevalence and risk factors for PoSH.