For patients with kidney disease, there is often a fear of uremia, and there are many related terms on the Internet that are easily confused, such as renal insufficiency, renal failure, uremia, etc. Is the presence of elevated creatinine uremic syndrome? This is done by calculating the glomerular filtration rate (eGFR) using a formula. The e in this means estimated, which means calculated according to the formula method. There is an accepted definition and staging of chronic kidney disease (CKD). It means that there are problems with kidney function (mainly laboratory tests of blood and urine) or kidney structure, and these problems persist for more than 3 months, which is chronic kidney disease. Staging is based on the level of glomerular filtration rate, which is abbreviated as GFR, and can be calculated based on the C-G formula or the MDRD formula. CKD stage 1: GFR ≥90 ml/min stage 2: GFR 60-89 ml/min stage 3: 30-59 ml/min stage 4: 15-29 ml/min stage 5: <15 ml/min If a male patient, 30 years old, with blood creatinine 133umol/L, calculates his eGFR as 55 ml/min according to MDRD, then it is CKD stage 3 stage. So is CKD stage 3 a uremic syndrome? Not yet! Because in the past, chronic renal failure was divided into four stages according to the degree of renal impairment: (1) renal reserve capacity decline, also known as renal insufficiency compensatory stage, the GFR of this stage is 35%-70% of normal, about 30-60ml/min; (2) azotemia stage, also known as renal insufficiency decompensatory stage, the GFR of this stage is 21%-35% of normal, about 25ml/min; (3 (3) renal failure, when the GFR is 11-20% of normal, about 10-15 ml/min; (4) uremic phase, when the GFR is less than 10% of normal, i.e. <10 ml/min. Thus, the azotemia phase corresponds to about stage 3 of the K/DOQI chronic kidney disease classification, the renal failure phase to about stage 4, and the uremic phase to about stage 5. Only patients with CKD stage 5 are uremic in the traditional sense. Therefore, like the male patient just now, his eGFR only reaches below 15 ml/L when his blood creatinine reaches above 400 umol/L, and this stage can be called uremic syndrome.