Can You Brush Your Teeth While Fasting for a Blood Test?

Can You Brush Your Teeth While Fasting for a Blood Test?

Many medical tests require fasting beforehand, including blood draws to check cholesterol, blood sugar, and other levels. During fasting, you cannot eat or drink anything besides water. But can you brush your teeth, or will that break your fast?

Brushing your teeth requires some minimal intake of toothpaste and water. However, most doctors consider this acceptable when fasting for routine blood work. Here's a closer look at the rationale and best practices around oral hygiene and fasting.

Purpose of Fasting Before a Blood Test

Fasting is required before most blood tests to ensure accurate results. Eating food can impact and artificially raise certain measurements like:

• Glucose
• Insulin
• Triglycerides
• Cholesterols

When you fast, your body achieves a baseline equilibrium unaffected by recent food intake. This gives your doctor the most standardized, reliable numbers from your blood test.

Fasting guidelines vary but commonly require 8-12 hours without food or drink, other than water and sometimes black coffee or tea.

Does Brushing Your Teeth Break a Fast?

Brushing with toothpaste introduces a minimal amount of fluoride and chemicals into your mouth, which you inadvertently swallow. The same goes for any water you sip while brushing.

However, most medical experts consider a small sip of water and residue from toothpaste to be perfectly acceptable during a routine pre-blood draw fast. It does not impact test results in any significant way.

With that said, be careful not to swallow toothpaste excessively. Use a pea-sized amount and spit thoroughly after brushing. Rinsing your mouth out with water is fine as well.

Oral Hygiene Importance While Fasting

Although you don't want to overindulge with mouthwash, you also shouldn't neglect oral hygiene while fasting. Brushing your teeth before a blood test offers several benefits:

• Prevents bad breath during your appointment
• Reduces bacteria growth in your mouth over hours of fasting
• Decreases risk of plaque, tartar, and cavities
• Removes food debris that could otherwise decay between teeth

The mechanical act of brushing also stimulates your gums and keeps your mouth feeling refreshed. Just be mindful not to swallow large quantities of toothpaste.

Brushing Your Teeth Tips While Fasting

Here are some tips for brushing your teeth during a pre-blood test fast:

• Use a pea-sized amount of toothpaste to minimize excess.
• Brush for 2 full minutes, carefully covering all surfaces.
• Take small sips of water to rinse instead of swishing mouthwash.
• Spit thoroughly into the sink after brushing to avoid swallowing residue.
• Bring a small toothbrush and toothpaste to brush after your test if needed.
• Chew sugar-free gum after brushing to stimulate saliva production.

Your regular oral hygiene routine of twice daily brushing is fine while fasting. Just be conscious not to ingest large amounts of toothpaste, mouthwash, or water unnecessarily.

When to Avoid Brushing While Fasting

In most cases, it's perfectly fine to brush your teeth as normal when fasting for routine bloodwork. However, you may need to avoid it in certain situations:

• Fasting for surgery - stricter limits may apply
• Fasting for a cholesterol test - be more careful about swallowing water
• Fasting before a glucose tolerance test - no toothpaste or rinsing allowed
• If you have a history of vomiting while brushing

For major medical procedures requiring complete fasting, oral hygiene may need to lapse briefly. Cholesterol testing is also quite sensitive to water intake. Get specific guidance from your doctor for any test beyond a simple blood draw.

Precautions if You Can't Brush While Fasting

If you cannot brush before a test due to medical instructions, take these precautions:

• Brush and floss thoroughly the evening before
• Scrape your tongue before bed to decrease bacteria
• Chew gum in the morning to stimulate saliva flow
• Swish just water in your mouth and spit before your appointment
• Bring breath mints, mini toothbrush, and small toothpaste

Resume your normal oral hygiene immediately after your test. Temporary lapses are unlikely to cause lasting harm, especially if you brush well before and after.

Foods That Don't Require Fasting

Many blood tests still allow clear liquids up to 2 hours beforehand. These approved options can help freshen your breath while technically not breaking your fast:

• Water
• Black coffee or plain tea
• Apple juice
• White grape or white cranberry juice
• Clear broth
• Popsicles without pulp or fruit pieces
• Hard candies like mints or gummy bears

Drink plain water after consuming any beverages besides water or black coffee to cleanse the mouth. Limit yourself to a few sips.

Key Takeaways

In most cases, it's absolutely fine to brush your teeth as part of your normal oral hygiene routine before a routine blood test requiring fasting. Just avoid excess swallowing of toothpaste residue or water.

Check with your doctor about any special restrictions if undergoing surgery or specific sensitive tests beyond a simple blood draw. Otherwise, brushing your teeth while fasting helps promote oral health without jeopardizing test results.

Make sure to spit thoroughly after brushing and limit water intake to occasional small sips. With these precautions, you can keep your mouth clean and breath fresh throughout a brief fast before your bloodwork.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.