What could be the cause of impaired renal function, as indicated by a glomerular filtration rate (GFR) of 68, with otherwise normal laboratory results?

Differential Diagnosis for a GFR of 68 with Otherwise Normal Labs

Single Most Likely Diagnosis

• Aging: A GFR of 68 can be a normal finding in older adults, as kidney function naturally declines with age. This diagnosis is likely if the patient is elderly and has no other symptoms or lab abnormalities.

Other Likely Diagnoses

• Dehydration: Dehydration can cause a temporary decrease in GFR. This diagnosis is possible if the patient has been experiencing vomiting, diarrhea, or excessive sweating.
• Medication side effects: Certain medications, such as NSAIDs, can decrease GFR. This diagnosis is possible if the patient is taking medications that are known to affect kidney function.
• Hypertension: Uncontrolled hypertension can damage kidney function over time, leading to a decrease in GFR. This diagnosis is possible if the patient has a history of hypertension.

Do Not Miss Diagnoses

• Diabetic nephropathy: Although the labs are otherwise normal, diabetic nephropathy can cause a decrease in GFR even in the absence of other abnormalities. This diagnosis is critical to consider, as untreated diabetic nephropathy can lead to end-stage renal disease.
• Kidney stones: Kidney stones can cause a decrease in GFR, especially if they are obstructing the flow of urine. This diagnosis is important to consider, as kidney stones can cause severe pain and other complications if left untreated.

Rare Diagnoses

• Polycystic kidney disease: This genetic disorder can cause cysts to form on the kidneys, leading to a decrease in GFR. This diagnosis is rare, but it is important to consider if there is a family history of the disease.
• Glomerulonephritis: This group of diseases can cause inflammation and damage to the kidneys, leading to a decrease in GFR. This diagnosis is rare, but it is important to consider if the patient has a history of autoimmune disorders or other systemic diseases.
• Vasculitis: This group of diseases can cause inflammation and damage to the blood vessels, including those in the kidneys, leading to a decrease in GFR. This diagnosis is rare, but it is important to consider if the patient has a history of autoimmune disorders or other systemic diseases.