Creatinine: Measures the level of creatinine, a waste product produced by muscle metabolism. Indicates how well the kidneys are filtering waste from the blood. Can signal if sleep problems may be related to kidney function.

Experiencing Symptoms: Such as insomnia, frequent waking during the night, fatigue, or muscle weakness.

Doctor's Recommendation: If a healthcare professional suggests checking your cortisol or creatinine levels for a more detailed health assessment.

Special instructions: Sample must be collected in the morning Monday through Thursday.

Look out for signs such as swelling or puffiness, especially in your arms and legs, alterations in your urination frequency or volume, and sleep issues like frequent nighttime urination or restless legs, which could signal creatinine level changes and potential kidney function concerns.