Urine osmolality

Why is urine osmolality low in post renal failure?

Why does in acute glomerulonephritis , specific gravity &urine osmolality increase ?Shouldn't kidneys loss the ability to concentrate the urine?

I drink a lot of water throughout the day. My random urine osmolality was 910 mOsml/kg. My random urine sodium was 90 mmol/L. My serum sodium is always on the low normal range and has been mildly low at times. Is this siadh?

My random urine osmolality test was 910 mOsmol/kg. My random urine sodium was 81 mmol/L. My blood sodium levels are low normal. I was well hydrated for these tests. My symptoms are bad muscle cramping with exercise. Is this diagnostic of siadh?

I have mildly low sodium blood levels. My random urine sodium is 80 mmol/L. Urine osmolality is normal. My symptoms are bad muscle cramping, thirst, and frequent urination. Im not on any medications and I eat a normal diet. Could this be siadh?

My hematocrit is 53 and my hemoglobin is 18, hemoconcentration. My blood sodium has been 133-135. My random urine sodium is 80 mmol/L. Random urine osmolality is in 900. My symptoms are chronic muscle cramping. Is this hypovolemic hyponatremia?

I am 20 years old with medical issues, I was ordered for blood tests and urine test. My ketones were 15, Squam Epithel, UA was 5-10, OSMOLALITY was at 272L. They were all flagged abnormal should I be worried?

These are some blood test results and maybe urine, RBC 3.93 M/mcL ,Hgb POC 11.9 g/DL, Sodium Lvl 132 mol/L,Osmolality 256 mOsm/kg. They r low. Ideas?

Im a 30 year old male. My serum sodium is 135 mmol/L. My random urine sodium is 85 mmol/L. My random urine osmolality is 910 mOsmol/kg. My kidney function is in the normal range. My symptoms are muscle cramping and fatigue. Could this be siadh?

Why is urine oily.