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how long do i fast for a fasting blood test

A 46-year-old member asked:
Dr. Gurmukh Singh
49 years experience Pathology
In a way, yes: If you fast for longer than a day or so, it will alter some blood chemistries. Fasting tests are usually set for an overnight fast, or a 12 hour fast. ... Read More

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A 19-year-old male asked:
Dr. Robert Killian
28 years experience General Practice
Eight to Twelve: Eight to twelve hours should suffice.
A 21-year-old female asked:
Dr. Elena Roukhadze
14 years experience Pathology
No: No need to fast to determine bilirubin levels.
A 44-year-old female asked:
Dr. Ed Friedlander
44 years experience Pathology
No: You should keep supplementing with vitamin D, unless you want to get it through your diet or through sunshine. This is a common and serious deficiency ... Read More
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A 23-year-old female asked:
Dr. Natalie Hodge
26 years experience Pediatrics
Differential Dx: Treat Low Glucose with Glucose! The duration depends on the cause; there are many! A glucose of 32 in a 23 year old is definitely not normal! Firs ... Read More
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A 43-year-old male asked:
Dr. Vahe Yetimyan
51 years experience General Practice
12 hours.: One may be asked to maintain a-12 hour fast and give the blood for testing in the night. See your doctor for other ways to test your blood sugar.
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A 35-year-old male asked:
Dr. Ed Friedlander
44 years experience Pathology
No: Your kidney failure may be something as simple as the transient effect of a painkiller such as ibuprofen, or something as troublesome as interstitial ... Read More
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A 50-year-old male asked:
Dr. James Ferguson
46 years experience Pediatrics
Gas=multiple factors: The gas you pass includes air you swallow when eating plus the gas generated by gut bacteria that live off undigested material. If you don't absorb s ... Read More
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A 54-year-old female asked:
Dr. Geoffrey Rutledge
41 years experience Internal Medicine
Normal: The numbers are essentially within normal limits. Upper normal for potassium is 5.1, but due to handling errors, slight elevations are often / usually ... Read More
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