If a blood test showed your kidneys were healthy why would a kidney ultrasound come back abnormal?

Blockage. Kidney ultrasounds evaluate blood flow into the kidney and urine flow out of the kidney. Often, kidney function can be preserved long after blood flow or urine output begins to deteriorate. Also ultrasounds can pick up cysts and tumors that blood tests don't.
Many reasons. There are many anatomical abnormalities of the kidney that dont necessarily cause kidney failure. See a urologist to sort it out.

Related Questions

I was sent to get a blood test because of kidney stones that a sonogram revealed I have. My results show that my MPV is high at 12.7 Is that normal?

Platelets. MPV=mean platelet volume This is a little used value in thehemograom, with only weak correlation with disease states. Like red cells, younger platelets tend to be bigger, and stress reactions may prompt earlier release from the marrow. Many possible causes, but little utility in isolation.

Can a blood test miss a kidney stone that was discovered by an ultrasound?

Not aware. Of any "blood test" for kidney stones, It is a clinical or radiographic diagnosis. A urinalysis is the only useful "lab test".
Yes. No blood test can diagnose a kidney stone. The diagnosis is usually made by using a medical imaging study- Ct, X-Ray, US in the presence of symptoms suggesting a kidney stone. A urineanalysis may help in establishing the acuity. Hope it helps.
Yes. Blood test won't diagnosis kidney stones. Symptoms, physical exam, and urine test may help with diagnosis but imaging with CT scan, ultrasound or x-ray would be the main way that kidney stones are found.

I had 3 blood test for serum cheatinine last one was 2.1. Had ultrasound. Dr. Sent me letter 6 months ago kidneys look good. Should I be concerned?

Yes. Serum creatinine correlates with msucle mass and above 1.6 mg/dl is abnormal for even a muscular man, unless he's elderly at which time some loss of kidney functions is expected. I'm glad you are being followed; we can be confident you have some mild kidney damage, but this happens to all of us as we age.
Slow kidneys. Although they look good on ultrasound, creatinine of 2.1 means your kidneys are definitely slow. Ultrasound rules out cancer, stones and blockages. But the slow kidney is called chronic kidney disease (ckd). It is recommended that you see a nephrologist who may or may not change things. If your doctor is a nephrologist then you are okay.

30 yr old female. Had renal ultrasound for micro hematuria. Left ureter jet wasn't firing. Kidney blood test normal. Could this be cancer?

Blood in urine. It is not likely that you have a cancer. I see you are taking anticoagulant meds. This can predispose to hematuria. Given the ultrasound finging of what could be slowed urine passage thru one ureter, coupled to microhematuria, I recommend further dialogue with your docs. An IVP or better, a CT-IVP is a valuable next test.

Felt sick month ago. Found elevated ferratin and billirubin. Ab ultrasound ok. Still feel horrible today. Blood test now normal except slight icterus. Extreme fatigue. Pain below navel&lower back.???

More info. This is a complex question which can't be answered without much more info, test results, etc. Best to see a gastroenterologist.
Hemochromatosis. Get tested for hemochromatosis, a genetic mutation which causes iron overload in the liver. It causes many nonspecific symptoms of generalised fatigue, joint pain, and malaise, and affects the liver and other organs. There is a blood test to detect the mutation. Liver MRI may show iron deposits, and liver biopsy will confirm the diagnosis. See a gastroenterologist ASAP.