Good to knowOne result rarely tells the whole story. Your provider looks at your results together with your symptoms, exam, and other tests.
What the test is
Some medicines and caffeine can affect results.
Why it's done
- Spells of pounding headache, sweating, and fast heartbeat
- Very high or hard-to-control blood pressure
- An adrenal lump on a scan
Getting ready and what happens
- Avoid caffeine and nicotine beforehand. Ask about medicines like some antidepressants. For blood, you may lie down 30 minutes first.
How the test is done
- A health worker cleans the skin, puts a band around your arm, and draws blood from a vein with a small needle. It takes a few minutes.
- Or a 24-hour urine collection.
What the results mean
Very high
Imaging looks for a tumor, which is usually treated with surgery.
Questions to ask your provider
- What do my results mean for me?
- Do I need to repeat this test or have other tests?
Risks
A blood draw is very safe. You may have slight pain or a small bruise where the needle went in.
Related conditions
Related tests
Sources
Last updated 2026-11-13.