Final answer:
Substances that indicate a problem with renal function include protein, creatinine, red blood cells, and uric acid. The presence of these substances in the urine suggests that the kidneys are not properly filtering waste from the blood.
Step-by-step explanation:
To identify which substances would indicate a problem with renal function, we need to consider the role of the kidneys and what would indicate their impairment. The kidneys are responsible for filtering waste products from the blood and excreting them in the urine. Simple urine tests like routine urinalysis can help detect potential kidney problems early on.
The presence of the following substances can indicate a problem with renal function:
- Protein: Usually not filtered out in great quantities due to its size, the presence of proteins such as albumin in the urine can indicate damage to the glomeruli.
- Creatinine: An elevated serum creatinine level is typically detected in cases of renal dysfunction as it is a byproduct of muscle metabolism that the kidneys usually filter out.
- Red blood cells: Hematuria, or blood in the urine, can indicate various forms of renal pathology.
- Uric acid: While related to the metabolism of nitrogenous substances, elevated uric acid can be associated with multiple conditions, including renal dysfunction.
However, sodium levels alone do not specifically indicate kidney function issues without further context. Hence, sodium is not selected as an indicator of renal dysfunction in this question.