Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errorsOnly some blood tests require fasting. Whether you need to avoid food depends on the exact test and the instructions for your order—not simply on having blood drawn. If fasting is prescribed, it is usually for 8 to 12 hours, and plain water is generally allowed. Check with the ordering clinician or laboratory if you are unsure.
Which blood tests require fasting?
Fasting is test-specific, and examples below are not a complete list. MedlinePlus says fasting glucose and an oral glucose tolerance test (OGTT) require fasting; random glucose, hemoglobin A1c (HbA1c), and the one-hour gestational glucose challenge do not. A routine lipid panel and a CBC ordered alone also generally do not require fasting. A BMP may, because it includes glucose. For a combined order, the preparation for one test can affect the whole blood draw.
As an Amazon Associate I earn from qualifying purchases.
| Test or order | General preparation | Important distinction |
|---|---|---|
| Fasting plasma glucose | Fasting required, typically at least 8 hours (MedlinePlus). | Confirm the timing and preparation on your order. MedlinePlus: Blood Glucose Test |
| Oral glucose tolerance test (OGTT) | Fasting required before the test. | The test includes a glucose drink and later timed blood samples; follow the test center’s protocol. MedlinePlus: Blood Glucose Test |
| Random blood glucose | No fasting required. | Different from a fasting plasma glucose test. MedlinePlus: Blood Glucose Test |
| Hemoglobin A1c (HbA1c) | No fasting required. | It reflects longer-term average blood glucose, rather than only a fasting level. MedlinePlus: Blood Glucose Test |
| One-hour gestational glucose challenge | No fasting required for the challenge. | A high result may lead to a separate OGTT, which requires fasting. MedlinePlus: Blood Glucose Test |
| Standard lipid panel | Either fasting or nonfasting is acceptable for routine assessment under the 2026 ACC/AHA guideline. | Fasting is recommended in certain circumstances; see the lipid section below. 2026 ACC/AHA dyslipidemia guideline |
| Complete blood count (CBC) | Usually no special preparation when ordered alone. | Other tests drawn at the same time may require fasting. MedlinePlus: Complete Blood Count (CBC) |
| Basic metabolic panel (BMP) | May require an eight-hour fast. | It includes glucose; follow the instructions for your order. MedlinePlus: Basic Metabolic Panel (BMP) |
| Comprehensive metabolic panel (CMP), liver or renal tests | Requirements depend on the specific tests and why they were ordered. | Do not infer preparation from the panel name alone. MedlinePlus: Fasting for a Blood Test |
| TSH | TSH alone does not generally call for fasting instructions on the MedlinePlus page. | Other tests in the same order may require fasting. MedlinePlus: TSH Test |
Do I need to fast for a cholesterol test?
Not automatically. For routine assessment, the 2026 American College of Cardiology and American Heart Association dyslipidemia guideline recommends either a fasting or nonfasting standard lipid profile to establish lipid levels, estimate cardiovascular risk, and guide treatment.
Free tools Windows power users keep installed
One-click scans. No signup required.
The guideline recommends a fasting profile in selected cases: a family history of dyslipidemia or premature atherosclerotic cardiovascular disease, a known or suspected triglyceride-metabolism disorder, or a nonfasting triglyceride result of at least 400 mg/dL (4.5 mmol/L). In those circumstances, fasting can help estimate LDL-C. Follow the clinician’s instructions for your particular order.
#1 Best Overall
- Quick Results: Learn your blood type in just a couple of minutes with this easy-to-use testing kit
- Simple Interpretation: Easily understand your blood type group with clear and straightforward results
- Permanent Record: Keep as a permanent record of your blood type on the durable card for your records or safekeeping
- Reliable Accuracy: Offers a reliable and accurate way to learn your blood type using proven testing technology
- Convenient Home Use: Can be used conveniently at home without the need for laboratory visits
Can I drink water before a fasting blood test?
Generally, yes: MedlinePlus describes fasting as avoiding food and drinks other than plain water for several hours before the test. The usual fast is 8 to 12 hours, but use the exact duration and any additional restrictions given by the ordering clinician or laboratory. MedlinePlus: Fasting for a Blood Test
During the fast, MedlinePlus advises avoiding gum, smoking, and exercise. Do not assume that every test in a group has the same preparation rule; clarify the full order if its directions are unclear.
Rank #2
- SIMPLE DAILY BLOOD PRESSURE TRACKING - Record your systolic, diastolic, pulse, and heart rate in one clean table. Perfect for seniors, adults, caregivers, and anyone monitoring BP at home.
- HANDY A5 SIZE WITH 110 PAGES - This compact A5 notebook (5.8 × 8.3 inches) fits easily in bags or clinic folders. Includes 110 pages with plenty of writing space for notes, symptoms, reminders, and observations.
- COMPLETE PERSONAL & MEDICAL INFO PAGE - The first page includes Book Belongs To details: Name, Telephone, Mobile, Email, Website, Address, Blood Group, Height, Weight, Doctor Information, and Emergency Contact.
- FLEXIBLE MONTH & YEAR FORMAT - Each daily log page includes a blank Month and Year section so you can start using the book any time of the year.
- ORGANIZED DAILY TABLE FOR ACCURATE LOGGING - Every page includes a clear table with Date, Time, Systolic, Diastolic, Pulse, and Notes. helping you stay consistent and in control of your heart health.
Can I eat before a CBC or other routine blood work?
If a CBC is the only test ordered, it usually requires no special preparation. But a blood draw can include several tests, and another test may require fasting. A BMP, for example, may require an eight-hour fast because it includes glucose. CMP, liver, and renal test requirements depend on the exact tests and reason for the order, so check rather than relying on the panel name.
Quick Recap
Best Value
- 【Effortless Daily Glucose Tracking】 Easily record 7 daily blood sugar readings (before/after breakfast, lunch, dinner, bedtime) with a clear, pre-formatted grid by the dedicated blood sugar log book. Simple to use with no complicated setup, keeping all your glucose data organized in one place. Never miss a reading again, and keep all your critical glucose data organized in one easy-to-access place
- 【Compact Design for Diabetics】 This compact diabetes blood glucose log books measures just 3.94 x 5.51 inch. Slim and pocket-sized, this diary fits easily in your pocket, purse, or glucose kit. Lightweight and portable, it’s ideal for daily use at home, work, or travel, perfect for consistent diabetes management
- 【13-Week Long-Term Tracking】 Each blood sugar log book supports 13 full weeks of continuous glucose monitoring, helping you track long-term trends and see how diet, medication, and daily routines affect your levels. The diabetic log books the ideal tool for consistent, long-term diabetes self-care
- 【Simple, Practical Format】No complicated charts or confusing layouts—user-friendly layout works with any blood glucose monitoring kit. Just log and go—clear, consistent data makes it easy to share trends with your doctor for better care
- 【Durable, High-Quality Daily Use】 Built to withstand frequent handling, each blood glucose record book features thick, smudge-resistant paper that prevents ink bleed and a sturdy, crease-proof cover that holds up to daily use. The 10-pack design ensures you have a long-term supply for yourself, or to share with family members managing diabetes. Invest in a logbook that’s as reliable as your health routine
Rank #3
- 【Advantage Set】You will receive 10 books blood sugar logs, which are sufficient for your daily use and replacement, and track your blood pressure, heart rate and medication in detail to help improve health management and ensure timely treatment.
- 【Durable Material】Our glucose book log is made of high-quality paper with rich texture, comfortable touch, smooth surface and easy writing, so you can easily fill it out during use.
- 【Continuous Tracking】The diabetes journal allows recording 7 times a day, before and after meals in the morning, afternoon, evening and night, and each can be recorded for 14 weeks, which helps to continuously track blood pressure and help identify patterns over time.
- 【Easy to Carry】This blood pressure log book is suitable for 3x4inch in size. Its lightweight design is easy to carry and can be easily stored in a bag, allowing you to update your health records anytime, anywhere.
- 【Wide Application】Our blood glucose record book is suitable for diabetics, prediabetes. This simple and convenient way to track your daily blood sugar levels. You will easily discover trends and patterns in the records and conduct timely health management and treatment.
What should I do if I ate, drank, or take medicine before the test?
- Check the order. Look for explicit fasting instructions and the required duration. If they are missing or unclear, contact the ordering clinician or laboratory before the appointment.
- Tell the lab if you did not complete a required fast. If you ate or drank during the fasting period, disclose what happened. The test may need to be rescheduled.
- Do not stop medication or supplements on your own. Ask the clinician or laboratory whether to take prescription medicines, vitamins, or supplements; instructions depend on the test, and some medicines can affect results. MedlinePlus: How to Prepare for a Lab Test and MedlinePlus: TSH Test
- Plan to eat afterward. You can eat once the test is over. MedlinePlus notes that a snack may help if you feel light-headed. MedlinePlus: Fasting for a Blood Test
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
