Comparisons
CRP vs ESR
Both are 'inflammatory markers', and they are often ordered together, but they measure different things at different speeds. CRP is a single protein that rises…
Creatinine vs eGFR
Creatinine is the thing that is measured; eGFR is the number the laboratory calculates from it. They appear side by side on every kidney blood test, and…
ECG vs echocardiogram
One records the heart's electricity, the other shows its structure and motion. They answer different questions and are usually both needed when heart disease…
CT vs MRI
Both produce cross-sectional images of the body, but by different physics: CT uses X-rays and is fast, MRI uses magnetic fields and radio waves and shows soft…
TSH vs free T4
TSH comes from the pituitary and free T4 from the thyroid, and they move in opposite directions. Reading them together tells whether a thyroid problem is mild…
HbA1c vs blood glucose
Blood glucose is a snapshot of one moment; HbA1c is a three-month average. Both diagnose diabetes, but they answer different questions and each fails in…
Atorvastatin vs rosuvastatin
The two high-intensity statins share a mechanism and most of their effects. They differ in potency per milligram, in how they are cleared, and therefore in…