The short answer
Primary care leans on a small number of well-understood tests. A complete blood count looks at the cells in your blood. A metabolic panel looks at kidney function, electrolytes and glucose. A hemoglobin A1c summarises blood sugar over recent months. A lipid panel measures cholesterol and triglycerides. A TSH screens thyroid function. Most laboratory orders you will ever receive from primary care are some combination of those, chosen because of a specific question.
What each test is for
| Test | What it measures | The question it answers |
|---|---|---|
| Complete blood count (CBC) | Red cells, white cells, platelets | Anaemia, infection, bleeding or clotting problems |
| Basic metabolic panel (BMP) | Electrolytes, kidney markers, glucose | Kidney function, hydration, electrolyte balance |
| Comprehensive metabolic panel (CMP) | The BMP plus liver markers and protein | The above, plus liver involvement |
| Hemoglobin A1c | Average blood sugar over recent months | Prediabetes and diabetes, and control over time |
| Lipid panel | Total cholesterol, LDL, HDL, triglycerides | Cardiovascular risk and treatment response |
| TSH | Pituitary signal to the thyroid | Whether thyroid function needs a closer look |
| Urinalysis | Urine chemistry and cells | Urinary infection, kidney involvement, glucose or protein |
What a CBC and CMP show, A1c and cholesterol results and TSH and thyroid testing go into each in more depth.
Why not just test everything
- Every test has a chance of an abnormal result that means nothing, and each one generates a repeat test, a worry and a bill.
- A test is only useful when the result would change something.
- Large panels ordered without a question produce findings nobody can put in context.
- Tests chosen for your history and symptoms answer faster and cost less.
How reference ranges work
A reference range describes where most results from a reference population fall. It is not a personal target, it varies between laboratories, and it shifts with age, sex, pregnancy, altitude and the method used. That is why a value just outside a range is often unremarkable and why a value inside it can still be a change worth explaining — and why we do not publish thresholds here for you to check your own results against.
How it works at Presence
The visit defines the question
Tests follow from history and symptoms, not from a menu.
The price comes before the order
Cash pricing is quoted first, and member pricing is set out on labs and imaging savings.
You go to a local collection site
Bring the order and photo identification, and follow any fasting instruction exactly.
Results return to the ordering provider
Common panels often come back quickly; some specialised tests take longer.
The results visit is the point
What is normal, what is not, what it means and what happens next — see what happens after an abnormal lab result.
This page explains what tests measure. It cannot interpret your results — discuss those with a licensed provider who has your history.