Gfr 72 and cretnine 1. 15. Suggest!

Let me try to explain to you in simpler terms. Most clinical settings do not have a way to measure GFR (glomerular filtration rate) directly. Most of the time, serum creatinine is used to estimate GFR.    There is disagreement about whether or not to diagnose CKD in older people with an eGFR of 45 to 59 mL/min/1.73 m2 when no other signs of chronic kidney disease are present (such as presence of protein in urine). GFR estimates are not very accurate and can be wrong. When age is used as a factor in estimating equations, the negative affects of a low GFR can be overestimated, especially in older adults. Also, the equation doesn't take into account the fact that GFR goes down with age, even in healthy older people. So, there are worries about both overdiagnosis of CKD in older patients with an eGFR of less than 60 mL/min/1.73 m2. It is recommended to get a urinalysis and an ultrasound of the abdomen to figure out what's going on. If they are normal but you still want to know how his kidneys work, you should measure his urinary creatinine clearance or direct GFR determination which is not done routinely.

Your father is aged 67 years and his serum creatinine is normal (1.15 mg/dL).  I guess you should not worry much.  But worth getting urine analysis and ultrasound abdomen and review with the reports.