Most people leave an annual physical having had blood drawn without ever being told what was in the tube. A week later a result arrives with a dozen abbreviations and a column of reference ranges, and the whole thing is filed unread.
This article explains what each standard test measures and why it is ordered. It also covers something less often discussed: not every healthy adult needs every test every year. Several of the big screening recommendations are tied to age and risk rather than to the calendar, which is worth knowing before assuming an annual draw is the standard of care.
At the end there is a comparison with what an on-site workplace biometric panel covers, because the two overlap considerably without being the same thing.
Key Insights
- Four tests cover most routine bloodwork: a complete blood count, a metabolic panel, a lipid panel, and a blood sugar measure.
- A comprehensive metabolic panel is 14 separate measurements: MedlinePlus lists glucose, electrolytes, kidney markers, and liver markers in a single draw.
- Screening is tied to age and risk, not the calendar: the USPSTF recommends diabetes screening for adults 35 to 70 with overweight or obesity, not for everyone annually.
- Blood pressure is the exception with the strongest backing: the USPSTF gives hypertension screening in adults a Grade A recommendation, and it needs no blood at all.
- A workplace biometric panel is narrower than an annual physical: it overlaps on the cardiovascular and metabolic markers and leaves out the rest.
The Complete Blood Count
Usually the first line on the page. A CBC measures the number and size of the cells in your blood, and according to MedlinePlus it covers red blood cells, which carry oxygen; white blood cells, which support the immune system; platelets, which help blood clot; hemoglobin, the iron-rich protein in red cells that transports oxygen; hematocrit, the share of whole blood made up of red cells; and mean corpuscular volume, the average size of the red cells.
A CBC with differential breaks the white cell count down into its five major types, which gives a clinician more to work with when something looks off.
What it is useful for: anaemia, signs of infection, and clotting problems. What it is not: a cardiovascular or metabolic risk assessment. A CBC can be entirely normal in someone with substantial undetected cardiometabolic risk, which is why it sits alongside the other panels rather than replacing them.
The Metabolic Panel
The workhorse of routine bloodwork and the test people understand least, largely because it is really fourteen tests wearing one name.
MedlinePlus lists the 14 substances a comprehensive metabolic panel measures: glucose, calcium, sodium, potassium, bicarbonate, chloride, albumin, total protein, ALP, ALT, AST, bilirubin, BUN, and creatinine.
Those group into four jobs. Glucose is the blood sugar snapshot. The electrolytes, meaning sodium, potassium, bicarbonate and chloride, describe fluid balance and are affected by hydration, medication, and kidney function. BUN and creatinine are the kidney markers. ALP, ALT, AST, bilirubin, albumin and total protein are the liver markers.
A basic metabolic panel is the shorter version, leaving out the liver measures. Which one gets ordered depends on why the clinician is testing.
The Lipid Panel
Four numbers, and the ones most directly connected to cardiovascular risk. MedlinePlus describes a lipid panel as measuring total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.
On the reference points that can be verified: MedlinePlus gives a desirable total cholesterol of less than 200 mg/dL for adults 20 or older. For LDL it gives optimal as below 100 mg/dL, with 100 to 129 near or above optimal, 130 to 159 borderline high, 160 to 189 high, and 190 or above very high, described as general ranges for healthy adults. For HDL, 60 mg/dL or greater is best, with low defined as below 40 for men and below 50 for women. For triglycerides, normal is below 150 mg/dL, borderline high 150 to 199, high 200 to 499, and very high 500 or above.
An important qualification that every source attaches: personal targets vary with risk. MedlinePlus notes that someone at high risk of a heart attack or stroke, or who already has heart disease, may be given an LDL goal of 70 or below. A number that is unremarkable for one person is a problem for another.
On fasting, the guidance has relaxed. MedlinePlus notes a fast of 9 to 12 hours may be required, while the American Heart Association says the test may be fasting or non-fasting depending on circumstances. Triglycerides are the number most affected by recent eating.
On whether a statin follows an abnormal result, the USPSTF recommendation is specific rather than general. For adults aged 40 to 75 with at least one cardiovascular risk factor and an estimated 10-year risk of 10 percent or higher, it is a Grade B recommendation to prescribe a statin. At a 10-year risk of 7.5 to under 10 percent it becomes Grade C, selectively offered. For adults 76 and older the USPSTF issues an I statement, meaning the evidence is insufficient either way.
Blood Sugar: Glucose and A1C
Glucose appears on a metabolic panel as a point-in-time reading. A1C is the more informative measure because it reflects average blood sugar over roughly the previous three months.
The American Diabetes Association sets the thresholds. For A1C: below 5.7 percent is normal, 5.7 to 6.4 percent is prediabetes, and 6.5 percent or higher indicates diabetes. For fasting blood glucose: below 100 mg/dL normal, 100 to 125 prediabetes, 126 or higher diabetes.
This is the area where routine testing finds the most that was previously unknown. The CDC reports 115.2 million US adults with prediabetes, more than 2 in 5, with 8 in 10 unaware, and its National Diabetes Statistics Report puts 2023 diabetes at 40.1 million people, 12.0 percent of the population, with roughly 11.0 million adults undiagnosed.
Who should be tested is narrower than you might expect. The USPSTF gives a Grade B recommendation to screen adults aged 35 to 70 who have overweight or obesity, with overweight defined as a BMI of 25 or higher and obesity as 30 or higher, and a lower cutoff of 23 or higher cited for Asian American adults.
The Test That Is Not a Blood Test
Worth a mention because it carries the strongest recommendation of anything discussed here and involves no needle.
The USPSTF gives screening for hypertension in adults 18 or older a Grade A, using office blood pressure measurement, and advises confirming a diagnosis with readings taken outside the clinic before starting treatment. Grade A is the highest the Task Force issues.
Given that the CDC reports 48.1 percent of adults have high blood pressure with only 22.5 percent controlling it, and that it usually has no warning signs or symptoms, it is the highest-yield two minutes of any physical. We cover it separately in what blood pressure screening catches at work.
Does Everyone Need Bloodwork Every Year
Not necessarily, and this is where the phrase annual physical does some unhelpful work.
The screening recommendations above are keyed to age and risk rather than to a yearly cycle. Diabetes screening is recommended for a defined age band with specific BMI criteria. Statin decisions depend on calculated 10-year risk. None of that translates into "draw blood every twelve months for everyone."
What is reasonable varies by person, which is a genuinely unsatisfying answer and the correct one. Age, family history, existing conditions, medications, and prior results all shift the calculation. The useful question to ask a clinician is not whether you need bloodwork but which tests are indicated for you and how often.
Where an annual cycle does earn its place is in producing a trend. A single result is a point. Three years of the same measurements show direction, and direction is considerably more informative than position. Our article on how often employees should get a check-up covers the frequency question from the employer side.
How This Compares With a Workplace Biometric Screening
The two overlap, and knowing where helps you avoid both duplication and false reassurance.
A workplace biometric panel typically covers blood pressure, a lipid panel, glucose or A1C, and body measurements including height, weight, BMI and waist. That is the cardiovascular and metabolic core of an annual physical, delivered in about twenty minutes at your own workplace. Our explainer on what a biometric screening is covers it in full, and how to read your biometric screening results walks through interpreting the numbers.
What a biometric panel generally leaves out is the rest of the metabolic panel, the CBC, thyroid testing, and any physician examination or history. It is also not a substitute for age-appropriate screening such as colonoscopy or mammography.
The honest summary: a biometric screening is narrower than an annual physical and far easier to actually attend. For the specific conditions it covers, which happen to be the common silent ones, that accessibility trade is usually worth making. It works best alongside a relationship with a primary care physician rather than instead of one.
How NDS Wellness Delivers Screening On-Site
NDS Wellness brings a mobile wellness clinic to the workplace and runs physician-led on-site biometric screening across first, second, and third shift, so employees are screened during paid hours without booking, travelling, or giving up a rest day.
Because a physician is present, results are explained in person rather than mailed as a printout, and findings warranting follow-up are referred rather than filed. Individual results stay confidential between the employee and the clinician, and employers receive de-identified aggregate reporting only.
See the wider program on our corporate wellness page.
