In a span of 8 months, both my dad and FIL have been diagnosed with high creatinine level in their blood stream. Dad with 50% of the kidney still in good working condition while my FIL diagnosed 3 weeks ago with less then 15%. This is all so sudden. FIL has been fine all along never missing his 3 time a week 18 hole golf session for the last 25 years. The only time he had a major operation was in 1998. A man of moderation in his consumption of food and drinks. Goes for his annual check-up. What went wrong? Was it the diet? The prescribed drugs consummed over time? Or just genetic?