Hi,
If you are referring to stage 1 chronic kidney disease, and your estimated GFR or Glomerular Filtration Rate is around 90, this suggests that there is normal kidney function but urine findings or structural abnormalities or genetic trait point to kidney disease. Management include observation, control of blood pressure and risk factors. Regular monitoring of creatinine, urinary protein, cholesterol may be done. Lifestyle changes like regualr exercise, healthy diet, and smoking cessation is also recommended. Hope this helps. Take care and do keep us posted.