Getting full blood work typically starts with a doctor’s order during an annual physical, but you can also order comprehensive panels yourself through direct-to-consumer lab services. The process involves choosing which tests you need, preparing properly (usually fasting for 8 to 12 hours), visiting a lab for a blood draw, and reviewing your results within one to a few days. Here’s how each step works and what to expect.
What “Full Blood Work” Actually Includes
There’s no single test called “full blood work.” The phrase usually refers to two foundational panels ordered together: a complete blood count (CBC) and a comprehensive metabolic panel (CMP). A CBC measures your red blood cells, white blood cells, and platelets, giving a snapshot of your immune function, oxygen-carrying capacity, and clotting ability. A CMP covers 14 different substances: glucose, electrolytes like sodium, potassium, chloride, and bicarbonate, plus kidney markers like blood urea nitrogen and creatinine, and liver enzymes including ALT, AST, alkaline phosphatase, bilirubin, and albumin. Calcium rounds out the panel.
Together, these two panels flag problems with your blood cells, blood sugar, electrolyte balance, kidney function, and liver health. Most doctors consider this combination the baseline for a “full” workup.
Common Add-On Tests
Beyond the CBC and CMP, many people want a more complete picture. A lipid panel measures total cholesterol, LDL, HDL, and triglycerides. A thyroid panel (TSH and sometimes T3/T4) checks whether your thyroid is over- or underperforming. Vitamin D and B12 levels reveal common nutritional deficiencies. Iron studies and ferritin show your body’s iron stores. Hemoglobin A1C provides a three-month average of blood sugar, which is more useful than a single glucose reading for spotting prediabetes.
C-reactive protein (CRP) is the most widely used marker for general inflammation in the body. Elevated CRP has been linked in large analyses to higher risk of heart disease and stroke. If you have joint pain, unexplained fatigue, or a family history of autoimmune conditions, CRP can be a useful addition. Hormone panels covering testosterone, estrogen, or cortisol are sometimes included for people investigating specific symptoms like fatigue, weight changes, or mood issues.
Three Ways to Get Blood Work Ordered
The most straightforward path is through your primary care doctor. At an annual wellness visit, your doctor can order any combination of panels and the visit itself is typically covered by insurance as preventive care. Specific tests like cholesterol screening and diabetes screening are covered at no cost under most insurance plans when you meet certain criteria: cholesterol screening for men 35 and older (or younger if at increased risk) and women 20 and older at increased risk, and diabetes screening for adults 35 to 70 who are overweight or obese.
If you don’t have a primary care doctor or want to skip the office visit, direct-to-consumer lab services let you purchase tests online and walk into a lab for a blood draw. Labcorp OnDemand, for instance, lets you browse and buy tests on their website. Behind the scenes, a contracted healthcare provider authorizes the order, so you don’t need your own doctor’s involvement. You then visit one of their patient service centers for the draw and access results through an online portal. Quest Diagnostics offers a similar self-pay model.
A third option is telehealth. Many virtual care platforms will write lab orders after a brief online consultation, which you then take to a local lab. This can be a good middle ground if you want a provider’s input on which tests to request but don’t want an in-person appointment.
How to Prepare for Your Blood Draw
If your panel includes glucose or a lipid panel, you’ll need to fast for 8 to 12 hours beforehand. Fasting means no food and no beverages other than plain water. Coffee, juice, soda, and flavored water are all off limits because they can alter your blood sugar and lipid readings. During the fasting window, you should also avoid chewing gum, smoking, and exercise, all of which can subtly shift your results.
Continue taking your regular prescription medications unless your provider specifically tells you to stop. Let the ordering provider know about any vitamins or supplements you take, since high-dose biotin, for example, can interfere with certain hormone and thyroid assays. Scheduling your draw first thing in the morning makes fasting easiest since most of the hours overlap with sleep.
What the Blood Draw Feels Like
A typical full panel requires two to four small tubes of blood, drawn from a vein in the inside of your elbow. The needle is in for about one to two minutes. If you’ve fainted during blood draws before or feel anxious about needles, tell the phlebotomist upfront. They can have you lie down instead of sitting upright, which significantly reduces the chance of feeling lightheaded.
Staying well hydrated in the hours leading up to your appointment (plain water is fine while fasting) makes your veins easier to find. If you know you have difficult veins, mention it so the phlebotomist can use a smaller needle or try a different site. Applying a warm compress to your inner elbow for a few minutes before the draw also helps veins become more visible.
How Long Results Take
Standard panels like the CBC and CMP are processed quickly. A large study of over 100 hospital-based laboratories found that 99% had basic metabolic panel and CBC results available by the morning after collection. In practice, if you go to a commercial lab like Quest or Labcorp, expect results for routine panels within one to two business days.
Specialized tests take longer. Thyroid panels were available next-day at about 89% of labs in that same study, meaning some take an extra day or two. Hormone levels, vitamin D, and certain antibody tests may take three to seven business days depending on the lab. Your results will typically appear in an online patient portal, and if anything requires prompt attention, most labs will also contact you by phone or mail.
Understanding Your Results
Every result on your report will appear alongside a reference range, which is the span of values considered normal. These ranges are established by testing a large group of healthy people, typically at least 120 individuals, and identifying the middle 95% of values. That means 5% of perfectly healthy people will fall slightly outside the range on any given test.
Reference ranges aren’t universal. They often differ by sex and sometimes by age. Ferritin is a clear example: the normal range for men (roughly 29 to 441 ng/mL) is dramatically higher than for women (roughly 8 to 193 ng/mL), reflecting natural differences in iron storage. Creatinine, a kidney marker, also runs higher in men. Different labs may also use slightly different ranges because they use different testing equipment, so comparing results from two different labs isn’t always apples to apples.
A single value slightly outside the reference range rarely means something is wrong. Patterns matter more than isolated numbers. A fasting glucose of 102 on one test might just mean you didn’t fast quite long enough, while the same reading on three consecutive tests points toward prediabetes. If anything looks abnormal, your provider will usually recommend retesting before jumping to a diagnosis.
What It Costs Without Insurance
If you’re paying out of pocket, costs vary widely depending on which tests you order and where you go. A basic CBC or CMP at a direct-to-consumer lab typically runs $30 to $60 per panel. Bundled “comprehensive wellness” packages that include a CBC, CMP, lipid panel, and thyroid screening generally fall in the $100 to $250 range. Individual add-ons like vitamin D, testosterone, or A1C usually cost $30 to $75 each. Quest Diagnostics provides self-pay price estimates through their website or by calling their billing line.
With insurance, preventive screenings ordered during an annual wellness visit are often fully covered with no copay, as long as the visit is coded correctly as preventive. The key is that your doctor uses a “well-person” diagnosis code as the primary reason for the visit. If tests are ordered to investigate a specific symptom or monitor a known condition, they may be billed differently and subject to your deductible. If you’re unsure, ask your doctor’s office whether the labs will be coded as preventive before your blood is drawn.
Choosing Which Tests to Request
If you’re healthy and just want a general checkup, a CBC, CMP, lipid panel, and A1C cover the most ground for the least cost. Add a thyroid panel if you have symptoms like unexplained fatigue, weight gain, or feeling cold all the time. Add vitamin D if you live in a northern climate, spend little time outdoors, or have darker skin, all of which increase deficiency risk. Add iron studies if you’re a menstruating woman, a frequent blood donor, or a vegetarian.
If you have a family history of heart disease, ask about high-sensitivity CRP and lipoprotein(a), which offer a more nuanced look at cardiovascular risk than a standard lipid panel alone. For people over 50, kidney function markers and a complete blood count become especially valuable for catching early changes. The goal isn’t to order every test available but to match the panels to your age, sex, symptoms, and risk factors so the results actually tell you something useful.