lab-guides

The vitamin A blood test measures retinol circulating in your blood, checking whether the level sits too low or too high — distinct from a beta-carotene test.

Mean corpuscular volume measures the average size of your red blood cells, reported as part of a complete blood count and read alongside the rest of the panel.

A white blood count totals the white blood cells in a blood sample as part of a complete blood count — the number alone cannot confirm any diagnosis.

A hemoglobin test measures how much of the oxygen-carrying protein is in your blood, almost always run as part of a complete blood count.

The vitamin E (tocopherol) test measures circulating vitamin E, checking absorption or whether a supplement has pushed the level too high.

A urinalysis checks appearance, concentration and substances not normally in urine — blood, protein, glucose, ketones, bilirubin — each item read separately.

A platelet count measures the small cell fragments that help blood clot — about 150,000 to 400,000 per microliter for adults, read against your own lab's range.

Phosphate is a mineral electrolyte for bones, energy and nerves, read beside calcium, vitamin D, PTH and kidney markers.

The sed rate (ESR) shows how fast red blood cells settle; faster settling is consistent with inflammation but does not say where or why.

CK is a muscle enzyme that a hard training session can push up before the draw. How to read your result and what to tell the clinician ordering it.

Parathyroid hormone controls calcium, phosphorus and vitamin D in the blood. How to read your PTH result alongside the calcium measured in the same draw.

Blood urea nitrogen tracks protein waste the kidneys clear — but dehydration and diet move it too, so it is only one measure of kidney function.