Muscle loss doesn’t usually announce itself with a loud warning. Instead, it tends to show up quietly, and perhaps you begin to notice that getting out of a chair feels harder than it used to, or carrying groceries takes more effort. We may notice these changes in ourselves, or caregivers may see these subtle losses of muscle strength, long before a diagnosis is ever mentioned. There are several simple tools that healthcare providers can use to help identify the underlying cause of the issue. A combination of lab tests, strength checks, and imaging can provide a clearer picture. These tests examine factors such as nutrition, inflammation, hormone levels, and even everyday strength, including how firmly someone can grip or how quickly they can walk.
For individuals and caregivers, understanding these tests better helps you speak confidently with the healthcare team, be informed, and recognize early signs of change.
Breakdown of Labs, Imaging, and Tests
| Test | What It Measures | How It Relates to Muscle Health |
| Serum Creatinine | By-product of muscle metabolism | Lower levels (when kidney function is normal) may reflect low muscle mass |
| Creatinine-to-Cystatin C Ratio | Balance between creatinine (muscle-derived) and cystatin C (kidney marker) | Lower ratios are linked to sarcopenia and frailty |
| Serum Albumin & Prealbumin | Proteins made by the liver | Low levels suggest poor nutrition, protein-energy malnutrition, or muscle wasting |
| 25-Hydroxy Vitamin D or 25(OH)D | Status of the main form of Vitamin D | Deficiency is linked with weaker muscles, impaired balance, and a higher fall risk |
| C-Reactive Protein (CRP) | Inflammation marker | High CRP signals chronic inflammation, which contributes to muscle breakdown |
| Hemoglobin A1c & Fasting Glucose | Blood sugar control | Poorly controlled diabetes accelerates muscle loss and frailty |
| Hormone Panels (testosterone, IGF-1, thyroid) | Various hormones are used to assess overall endocrine function and identify imbalances | Low testosterone, IGF-1, or thyroid imbalance can worsen sarcopenia |
| DXA Scan (not a lab, but imaging) | Lean body mass and fat distribution | The gold standard for body composition, which helps detect low muscle mass |
| Grip Strength & Gait Speed | Functional muscle strength and performance | Core diagnostic measures for sarcopenia alongside labs |