Cautions for blood sampling for catecholamines: 1. Stop using beta-blockers, a-blockers, diuretics and other drugs that affect test results for more than two weeks 2. Abstain from bananas, coffee, strong tea, chocolate, etc. the day before the test 3. Rest for more than one hour before blood sampling 4. Patients can take blood in a calm state or during an attack of symptoms 5. Put the specimen in a refrigerator freezer immediately after blood sampling and contact laboratory personnel for timely delivery