TLDR;
This video by Dr. Mitch Rice outlines ten common mistakes people make before getting their blood drawn, which can lead to inaccurate results and potentially incorrect diagnoses. These mistakes range from improper fasting and skipping medications to taking supplements that interfere with lab results and not being adequately hydrated. The video provides practical solutions for each mistake to ensure more accurate blood work.
- Fasting improperly by consuming flavored drinks.
- Skipping essential medications.
- Testing blood work while sick or inflamed.
- Taking supplements that interfere with lab results, like biotin.
- Not being hydrated enough.
- Not disclosing all prescriptions.
- Exercising the morning of the blood draw.
- Eating heavy, fatty meals the night before.
- Getting blood work done too soon after a medication change.
- Getting blood work done the day before a doctor's appointment.
Intro [0:00]
Dr. Mitch Rice introduces the importance of proper preparation before a blood draw. He emphasizes that mistakes like not fasting correctly or exercising beforehand can significantly alter blood work results, leading to misdiagnoses or inappropriate treatment plans. The video aims to guide viewers through ten common mistakes to avoid for accurate blood work.
Mistake #1 [0:45]
The most common mistake is not fasting properly. Many people consume coffee, mints, gum, tea, or lemon water, thinking it's acceptable. However, anything with flavor, even without calories, can stimulate insulin and adrenaline, skewing fasting glucose, insulin, and triglyceride levels, which are crucial for assessing metabolic health. The solution is to only drink plain water during the 6-8 hour fasting window before the blood draw.
Mistake #2 [2:05]
Skipping essential medications is another frequent mistake. Omitting medications like thyroid pills, antidepressants, or seizure medications can skew lab results. These medications are often meant to be taken daily to avoid unnecessary spikes or drops in blood work, which can delay diagnosis and treatment. For example, missing a daily dose of levothyroxine can falsely lower TSH levels. It's important to ask your doctor which medications to take on the morning of the blood draw and, if unsure, bring a list of medications to the lab for the phlebotomist to review.
Mistake #3 [3:12]
Testing blood work while sick, run down, or inflamed can also lead to inaccurate results. Conditions like a mild cold, allergy flare-up, or poor sleep can affect the immune system, temporarily raising white blood cell count, ferritin levels, and inflammatory markers like ESR and CRP, as well as blood sugar and cortisol levels. In some cases, patients have been mistakenly evaluated for autoimmune diseases due to having a cold on the day of their blood work. The solution is to reschedule the appointment for 5-7 days in the future if you're not feeling well.
Mistake #4 [4:12]
Taking supplements that directly interfere with lab results is a common oversight. Supplements like biotin, often taken for hair, skin, and nails, can significantly alter thyroid markers (TSH, free T4, and free T3) and cardiac markers like troponin. Other supplements like ashwagandha or rhodiola can affect cortisol patterns, while excessive vitamin D can change calcium levels, and too much zinc or copper can alter iron profiles. To avoid these interferences, stop taking supplements 2-3 days before the blood work. If on high doses of biotin (over 5,000 micrograms per day), stop at least 72 hours prior.
Mistake #5 [5:47]
Not being hydrated enough can also skew blood work results. Dehydration makes blood draws harder and can concentrate the blood, affecting electrolyte panels, especially BUN, creatinine, and hemoglobin levels. To counteract this, drink plenty of water the day before and about 16 ounces of water 20-30 minutes before the blood draw to ensure easier blood flow and more accurate results.
Mistake #6 [6:36]
Failing to disclose all prescriptions, including those obtained online or from wellness clinics, can cause confusion. Medications like testosterone, compounded thyroid hormones, peptides, or injectable weight loss drugs (e.g., semaglutide) can significantly alter blood work. For instance, undisclosed testosterone use can raise red blood cell count, potentially leading to unnecessary concern about red blood cell cancer. Disclosing all medications and supplements to your physician, even if you don't think they're relevant, can prevent misunderstandings and ensure accurate interpretation of results.
Mistake #7 [8:16]
Exercising the morning of a blood draw, especially vigorous exercise, can temporarily increase creatinine and creatine kinase levels, potentially mimicking muscle damage or kidney disease. It can also affect liver enzymes, glucose, and cortisol levels, which could resemble diabetes. Avoid intense exercise before blood work; light walking is generally fine, but save high-intensity workouts for after the blood draw.
Mistake #8 [8:57]
Eating heavy, fatty meals 12-18 hours before blood work can spike cholesterol and triglyceride levels, even if you fast for 6-8 hours beforehand. This is particularly important for individuals with elevated cardiovascular risk, metabolic syndrome, or PCOS. The night before, eat a lighter meal that is higher in protein and contains a decent amount of carbs, while avoiding high-fat foods.
Mistake #9 [9:42]
Getting blood work done too soon after a medication change is another common mistake. If you've just started a new thyroid medicine or statin, wait about 6-8 weeks before testing to see the effects. Testing too soon may not allow the body enough time to adjust to the medication, potentially giving a false impression of its effectiveness. Consult your doctor about how long to wait before checking labs after a medication change.
Mistake #10 [10:36]
Scheduling blood work the day before a doctor's appointment doesn't give the doctor enough time to review the results. Schedule blood work at least 5-7 days before your appointment to allow time for the results to come back and for your doctor to review and discuss them with you during the visit.
Rapid Fire Summary + IMPORTANT Message [11:23]
Dr. Rice provides a quick recap of the ten most common mistakes: drink only water when fasting, take only essential medications, postpone labs if sick, stop interfering supplements (especially biotin), stay hydrated, disclose all prescriptions, avoid intense exercise the morning of, keep dinner light the night before, wait 6-8 weeks after a medication change, and schedule labs 5-7 days before your visit. He also mentions a free PDF available in the description with all the information discussed.