Q: I hate not eating for hours and hours before a blood test.
Is it really necessary?-Craig M., Schenectady, New York
A: It all depends on what you're being tested for. If your doc is testing for diabetes using a fasting blood glucose or oral glucose tolerance test, you'll fast overnight (schedule the tests for early the next morning, if possible).
That's because your blood glucose level fluctuates a lot when you eat or drink anything but water, plain coffee or black tea.
But the test for your A1C levels-a measure of your average glucose level over the past three months-doesn't require fasting.
You also will need to fast for eight to 12 hours if you're having your B-12 or iron checked. If you don't fast like the doctor ordered, you could be misdiagnosed.
On the other hand, there are conflicting ideas about the importance of fasting before an HDL or LDL cholesterol check.
New guidelines published in the European Heart Journal and JAMA Internal Medicine in July 2016 say that, for blood lipid testing, "a nonfasting blood draw has many practical advantages."
Translation: Your doctor will let you know if you should fast.
In addition, measurements of kidney, liver and thyroid function, as well as blood counts, don't require fasting.
Tip: Have a blood test as part of your yearly physical exam.
Even if you get regular physical exercise, don't drink or smoke, always stick to a perfectly balanced diet and never go without adequate sleep, we'd like you to stay in touch with your doc so you can catch any emerging problems.
At that exam, your doc will also look at your ears, eyes, nose, throat, teeth and gums, lymph nodes and thyroid; listen to your heart and lungs; check for an STD; and make an evaluation of your overall appearance.
Q: Is there any difference between this year's flu shot and last year's?
And if there isn't, do I still need to get one?-John E., Lansing, Michigan
A: There always is a difference.
The influenza vaccine is adjusted to target the flu strains that experts predict will be most prevalent, which can change from year to year.
New vaccinations are based on information from 142 national influenza centers in 113 countries.
Scientists from the World Health Organization Collaborating Centers for Reference and Research on Influenza analyze the data and decide which strains of the virus are most likely to cause illness in the upcoming flu season.
That's why you should get inoculated annually.
Plus, protection from a yearly flu shot can add up: If you receive the flu vaccine every year for 10 years, you'll reduce your risk of getting the flu by over 70 percent.
And if you do get the flu, it'll be much less severe.
It also makes it 48 percent more likely you'll be alive and kicking 10 years later, because 10 years of consecutive flu vaccines substantially decreases your risk of heart attack and stroke.
And you're not the only one to benefit!
When you get an annual flu vaccine you help decrease hospitalization across the population from flu-related pneumonias or lung infections by more than 25 percent.
Vaccines have gotten a lot safer in the past 30 years.
The odds of an adverse reaction, relative to a beneficial effect, are about 1 in 40,000.
2017 flu vaccine facts:
- The nasal mist with a live attenuated influenza version (LAIV) of the vaccine is NOT recommended for anyone.
- Trivalent/three-component vaccine targets: A/Michigan/45/2015 (H1N1) pdm09-like virus; A/Hong Kong/4801/2014 (H3N2)-like virus; B/Brisbane/60/2008-like (B/Victoria lineage) virus. There's a high-dose version for those 65-plus.
- Quadrivalent/four-component vaccine contains, in addition to those above, protection against the B/Phuket/3073/2013-like (B/Yamagata lineage) virus.
- Anyone 6 months or older should be vaccinated. Pregnant women should receive their age-appropriate influenza vaccine.
- Needle-shy? Fluzone Intradermal Quadrivalent vaccine for folks 18-64 has a 90 percent smaller, 1.5-mm microneedle.
Mehmet Oz, M.D. is host of "The Dr. Oz Show," and Mike Roizen, M.D. is Chief Wellness Officer and Chair of Wellness Institute at Cleveland Clinic. Email your health and wellness questions to Dr. Oz and Dr. Roizen at [email protected].
(c) 2017 Michael Roizen, M.D. and Mehmet Oz, M.D.