Are you wondering if you need to fast before your blood draw? Well, the answer may be No, and here are a few reasons why…
First, most doctors now check for diabetes with a test called the hemoglobin A1c, which is a 3-month average of blood sugars. You do not have to fast for this test. This test is usually done yearly with your Annual Physical, but if you have diabetes or pre-diabetes it may be done more often.
Second, if you eat very lightly before checking your cholesterol, the values will not be far off from fasting values. Tea and coffee are fine, too, as long as you don’t use a huge amount of cream and sugar. That said – think twice before ordering a Big Mac at lunch and then getting the labs done in the afternoon. This will almost certainly skew your cholesterol levels.
If you are taking a statin medication, fasting will probably not make much of a difference on your cholesterol readings.
If you know you have high cholesterol, or if your doctor is thinking about increasing the dose of the medication based on the levels, then it is important to achieve an accurate measurement. In these cases, fasting will get you your best numbers.
Aside from cholesterol and blood sugar, there are a few other labs that require fasting, but these are not routinely performed for an Annual Physical. Your doctor will tell you when this is required. If you are not sure, it’s ok to ask your doctor.
So now you know – you really just have to fast for labs once a year, at most, for cholesterol readings! And either way, be sure to drink plenty of water.
