Hi my father kidney now working only 22 % have to...

Chronic kidney disease 
CKD is one of the complications that result in kidney injury and progressive loss of kidney function that progress over time to reach an end stage kidney disease to neccitate dialysis. Most cases of CKD result from Hypertension and Diabetes that affect kidney nephrons and cause progressive function loss. In cases of CKD its wise to take precautions to prevent progressive kidney function loss by proper blood pressure and diabetes control along avoidance of Non steriodal analgesics intake. Some cases of CKD are caused by immunolgic reaction like Lupus nephritis and the kidney could be improved by taking the proper management protocol to control the disease progress. You should consult your nephrologist periodically to check for stage of CKD and the needed replacement therapy if dialysis is needed.
Investigations 
After proper physical exam, BP should be checked and treated, DM should be at the normal range of blood sugar and Hbg A1C, Kidney function tests Urea , Cr and GFR estimation should be done .Electrolytes (K,Na,Ca,Cl) should be done on regulat basis, Kidney ultrasound to check for kidney stones, Urine analysis to check for crystals and protein level. Kidney biopsy should be done to diagnose the underlying cause of ESKD.
Causes of CKD

• Uncontrolled DM, HTN
• Drugs 
• Infections 
• Obstructing stones 
• Congenital cystic kidney disease 
• Lupus 

Our advice 
You are adviced to have a regular diet rich in minerals and vitamins, avoid large amounts of protein and salt intake. Consume plenty of water and avoid NSAIDS, Other nephrotoxic drugs and smoking.