Creatinine of 160 μmol/L does not allow estimation of glomerular filtration rate. 1. The most commonly used formula for calculating glomerular filtration rate in clinical practice is the CKD-EPI formula, which requires age, gender, ethnicity (whether black or not), and blood creatinine value, and there are also the classic MDRD formula, the simplified MDRD formula, and the Cockcroft-Gault formula, which can not be calculated by creatinine value alone. 2. Blood creatinine is not highly sensitive and is usually not elevated in the early stages of renal damage; when it is elevated, it means that glomerular filtration has been impaired by at least 50%. When the blood creatinine is found to be elevated, one should consult a regular hospital immediately and seek systematic diagnosis and treatment in order to obtain the best prognosis.