A blood-pressure cuff detects elevated pressure inside your arteries. Hypertension lab tests answer different questions: they can help show whether high blood pressure is affecting the kidneys, whether glucose or lipid abnormalities are adding cardiovascular risk, whether medicines are changing electrolytes or kidney function, and whether a selected secondary cause deserves investigation.
High blood pressure is often silent. A person can feel well while hypertension affects the heart, brain, blood vessels, kidneys, and eyes. Accurate blood-pressure measurement and focused laboratory testing are therefore complementary—not interchangeable.
Ulta Lab Tests provides access to many relevant blood and urine tests that patients can order online where available. Laboratory testing is informational and does not replace a physical examination, diagnosis, treatment plan, medication review, or professional medical advice.
Direct answer: A blood test cannot diagnose hypertension. Blood and urine testing can help assess kidney damage, cardiometabolic risk, electrolyte and medication effects, and selected secondary causes after repeated blood-pressure measurements identify a problem.
This article is the broad hypertension testing hub. A focused Primary Aldosteronism guide provides an in-depth explanation of one important hormonal cause.
Related pillar guides include Heart Health Blood Tests and Kidney Function Tests. For broader testing literacy, see The Complete Guide to Lab Tests and Blood Work.
Hypertension means blood is repeatedly pushing against artery walls above the recommended range. The 2025 AHA/ACC guideline uses the following adult categories.1
| Blood-pressure category | Systolic pressure | Diastolic pressure |
|---|---|---|
| Normal | Below 120 mm Hg | And below 80 mm Hg |
| Elevated | 120–129 mm Hg | And below 80 mm Hg |
| Stage 1 hypertension | 130–139 mm Hg | Or 80–89 mm Hg |
| Stage 2 hypertension | 140 mm Hg or higher | Or 90 mm Hg or higher |
For most adults, the overall treatment goal is below 130/80 mm Hg, with individualized considerations for some people.1 One high office reading does not necessarily prove sustained hypertension. Out-of-office confirmation with a validated home monitor or ambulatory blood-pressure monitoring is often appropriate before treatment begins.2
The useful distinction is not “lifestyle versus disease.” It is whether hypertension appears to reflect a common, multifactorial pattern or an identifiable condition or exposure that may change management.
Primary, or essential, hypertension is the most common form. It develops through interacting influences rather than one laboratory-detectable cause. These can include age and family history; kidney, vascular, and neurohormonal regulation; body weight and fat distribution; dietary sodium and potassium patterns; physical activity; alcohol use; sleep; chronic stress; and social or environmental conditions.3
High cholesterol and abnormal glucose regulation frequently cluster with hypertension and raise cardiovascular risk. They are important to measure, but they usually do not explain the blood-pressure elevation by themselves. Likewise, atherosclerotic plaque is not the primary cause of most hypertension. Laboratory testing in primary hypertension is used mainly to characterize risk, look for organ effects, establish a treatment baseline, and identify clues that point away from a routine multifactorial pattern.
Secondary hypertension can result from a medical condition, medication, or substance. It deserves greater attention when blood pressure is severe, begins unusually early, rises abruptly, becomes difficult to control despite appropriate treatment, or is accompanied by a suggestive laboratory or symptom pattern.
| Possible driver | Clues that may raise suspicion | How evaluation may begin |
|---|---|---|
| Kidney disease | Reduced eGFR, albumin or blood in urine, swelling, diabetes, or a known kidney disorder | Creatinine/eGFR, UACR, urinalysis, medication review, and sometimes imaging or nephrology evaluation |
| Primary aldosteronism | Resistant hypertension, low potassium, adrenal finding, sleep apnea, or a relevant family history; normal potassium does not exclude it | Aldosterone and renin interpreted together, usually as an aldosterone-to-renin ratio (ARR) |
| Obstructive sleep apnea | Loud snoring, witnessed breathing pauses, daytime sleepiness, obesity, or resistant hypertension | Sleep-focused clinical assessment and a sleep study; blood tests cannot diagnose sleep apnea |
| Renovascular disease | Abrupt or worsening hypertension, asymmetric kidneys, abdominal bruit, recurrent unexplained pulmonary edema, or selected kidney-function changes | Clinical assessment and targeted imaging—not a blood-test panel |
| Thyroid dysfunction | Palpitations, tremor, heat or cold intolerance, constipation, or unexplained weight change | TSH, followed by Free T4 when appropriate |
| Pheochromocytoma or paraganglioma | Episodic severe pressure with pounding headache, sweating, tremor, or palpitations | Clinician-directed plasma free or 24-hour urinary fractionated metanephrines |
| Cortisol excess | Progressive, characteristic clinical features rather than hypertension alone | A validated clinician-directed Cushing syndrome screening pathway; a random serum cortisol is not a screening test |
| Pregnancy-related hypertension | New high readings during pregnancy or after delivery, especially with headache, vision change, upper abdominal pain, swelling, or feeling unwell | Prompt obstetric or emergency assessment with clinician-directed blood and urine testing |
These examples are not exhaustive, and the same clue can have several explanations. Testing should follow a clinical question rather than the desire to “rule out everything.”4
Some prescription medicines, over-the-counter products, and substances can raise blood pressure or make it harder to control. Examples include NSAID pain relievers, decongestants and other sympathomimetics, stimulant medicines, estrogen-containing products, glucocorticoids, calcineurin inhibitors, some antidepressants, selected cancer therapies, heavy alcohol use, nicotine, and illicit stimulants. The amount of effect varies by person and exposure.4
Bring a complete list of prescriptions, nonprescription medicines, supplements, energy products, and substances to a healthcare visit. Do not stop a prescribed drug or change a dose to prepare for testing unless the prescribing clinician gives a safe plan.
High blood pressure increases stress on artery walls and makes the heart work harder. Over time, it is associated with coronary artery disease, heart failure, atrial fibrillation, stroke, cognitive decline, chronic kidney disease, and other cardiovascular complications.1
Laboratory testing connects the blood-pressure reading with the larger health pattern. Kidney markers may reveal filtration changes or albumin leakage. Glucose and lipid tests can identify additional cardiometabolic risk. Electrolytes and creatinine can help establish a baseline and monitor selected medications. Targeted tests can investigate a secondary cause when the pattern supports one.
Focused testing can organize the evaluation around five questions:
Blood testing cannot establish hypertension without blood-pressure measurements. It also cannot diagnose obstructive sleep apnea, show how much sodium someone eats from a serum sodium result, detect every medication-related cause, replace imaging for renovascular disease, or independently choose the right medication or target.
A focused laboratory evaluation is especially useful when repeated home or office readings remain elevated, stage 2 or resistant hypertension is present, pressure rises abruptly, a new blood-pressure medicine is started, or kidney, glucose, lipid, thyroid, or electrolyte results have been abnormal. Testing also becomes more important when diabetes, chronic kidney disease, cardiovascular disease, foamy or bloody urine, swelling, low potassium, or a suggestive hormonal pattern is present.
Not everyone needs every available test. The best plan begins with a defined question and escalates only when the blood-pressure pattern, medication profile, symptoms, history, or initial results justify it.
The 2025 U.S. hypertension guideline lists a routine initial evaluation that includes a complete blood count; serum sodium, potassium, calcium, and creatinine with eGFR; a lipid profile; fasting glucose or A1C; TSH; urinalysis; and UACR or a urine protein-to-creatinine ratio. An electrocardiogram is also part of the initial evaluation, although it is not a laboratory test.4
| Test | What it can show | Key limitations or preparation points |
|---|---|---|
| CBC with Differential and Platelets | Provides hemoglobin, hematocrit, red-cell, white-cell, and platelet context. | Does not diagnose hypertension or identify most secondary causes. |
| Comprehensive Metabolic Panel (CMP) or Basic Metabolic Panel (BMP) | Provides kidney, electrolyte, glucose, calcium, and medication-safety information; CMP adds liver-associated markers and proteins. | One abnormal result does not establish chronic disease. Serum sodium does not directly measure dietary salt intake. |
| Creatinine with eGFR | Estimates kidney filtration. Kidney disease can contribute to hypertension, and hypertension can damage the kidneys. | Creatinine varies with muscle mass, diet, hydration, acute illness, and some medicines. A normal result does not exclude albumin leakage. |
| Urine Albumin-to-Creatinine Ratio (UACR) | Detects albumin leakage and helps identify kidney damage and cardiovascular risk, even when eGFR remains relatively preserved. | Exercise, fever, infection, urinary or menstrual bleeding, dehydration, and acute illness can temporarily elevate it. Abnormal results often need confirmation. |
| Urinalysis Complete | Assesses blood, protein, glucose, cells, and other urinary findings that may point toward kidney, urinary, or metabolic problems. | Dipstick protein is not a substitute for quantitative UACR. |
| Hemoglobin A1C or fasting glucose | Evaluates glucose regulation and overlapping cardiometabolic and kidney risk. | Fasting requirements differ. Anemia, hemoglobin variants, pregnancy, and recent blood loss can affect A1C interpretation. |
| Lipid Panel | Measures total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides to help characterize atherosclerotic risk. | Interpret with age, history, medicines, tobacco exposure, and overall cardiovascular risk. |
| TSH, with Free T4 when appropriate | Evaluates thyroid signaling when thyroid dysfunction may be relevant. | Pregnancy, acute illness, medicines, supplements such as biotin, and assay methods can affect interpretation. |
The kidney relationship runs in both directions. Chronic kidney disease can contribute to hypertension, and persistent hypertension can damage the kidneys. That is why filtration and urine albumin should be examined together rather than relying on one creatinine value.5
Creatinine with eGFR estimates filtration. UACR looks for albumin leaking into the urine. A person can have a relatively preserved eGFR while UACR is already abnormal. Conversely, eGFR can fall without marked albuminuria in some kidney disorders. The 2025 hypertension guideline added UACR to the recommended initial evaluation for people with high blood pressure.6
Direct answer: Normal creatinine does not prove the kidneys are unaffected by hypertension. UACR can reveal albumin leakage before a major change in eGFR appears.
Potassium, sodium, bicarbonate or carbon dioxide, and kidney function matter because blood-pressure medicines can change electrolyte and filtration patterns. ACE inhibitors, ARBs, diuretics, and mineralocorticoid receptor antagonists can require follow-up testing depending on the drug, dose, kidney function, baseline results, and clinician’s plan.
A CMP or BMP often supplies much of this information efficiently. Stand-alone potassium, sodium, magnesium, calcium, or creatinine testing may answer narrower follow-up questions. Serum sodium is tightly regulated and is not a direct measure of salt intake.
Hypertension often travels with other cardiometabolic risks. A1C or fasting glucose can identify abnormal glucose regulation, while a lipid panel helps define atherosclerotic risk. Apolipoprotein B (ApoB) may add selected risk information when triglycerides are elevated or routine lipid measures are discordant, but it is not required for every person with hypertension.
These tests do not prove why blood pressure is high. They show part of the cardiovascular risk surrounding it.
Most adults do not need an indiscriminate endocrine, inflammatory, or autoimmune panel. Targeted testing becomes more useful when pressure is severe, resistant, early-onset, abrupt, episodic, or otherwise unusual, or when symptoms, medication history, potassium, kidney findings, or other initial results suggest a specific mechanism.
Primary aldosteronism is an adrenal hormone disorder in which aldosterone production is inappropriately high relative to renin. It can cause persistent or resistant high blood pressure and sometimes low potassium. The 2025 Endocrine Society guideline conditionally suggests screening people with hypertension when the setting can support appropriate interpretation and follow-up, using aldosterone and renin with an ARR; potassium supports interpretation.7
Normal potassium does not rule primary aldosteronism out. A focused option is the Aldosterone and Plasma Renin Activity Ratio Test. Medicines, potassium status, sodium intake, posture, timing, kidney function, and assay method can affect interpretation.
Go deeper: For ARR interpretation, medication interference, repeat testing, suppression testing, adrenal imaging versus adrenal venous sampling, and treatment monitoring, read Primary Aldosteronism: When a Hormone Disorder Drives High Blood Pressure.
Abnormal eGFR, UACR, or urinalysis can point toward kidney involvement, but laboratory results may not identify the anatomy or exact mechanism. Abrupt or rapidly worsening hypertension, selected kidney-function changes, recurrent unexplained pulmonary edema, or other vascular clues may require clinician-directed imaging. A broad blood-test panel cannot diagnose renal artery narrowing.
Loud snoring, witnessed breathing pauses, daytime sleepiness, obesity, and resistant hypertension can raise suspicion for obstructive sleep apnea. Laboratory testing may characterize associated glucose, lipid, and kidney risk, but diagnosis requires a sleep-focused evaluation and usually a sleep study.
TSH followed by Free T4 when appropriate may be useful when palpitations, tremor, heat or cold intolerance, constipation, unexplained weight change, or another thyroid pattern accompanies hypertension. An abnormal thyroid result deserves interpretation in context; it does not automatically prove that thyroid disease caused the high reading.
Episodic severe hypertension with pounding headache, sweating, tremor, or palpitations may justify clinician-directed plasma free metanephrines or 24-hour urinary fractionated metanephrines.8 These rare-condition tests are sensitive to stress, medicines, and collection conditions, so false-positive results require careful follow-up.
Cortisol evaluation belongs in a convincing clinical pattern rather than routine hypertension screening. A random serum cortisol is not a stand-alone screen for Cushing syndrome. Validated endocrine protocols are clinician directed; see the focused guide to Cushing syndrome testing.
When hypertension occurs with blood or protein in urine, edema, rashes, joint symptoms, or systemic inflammation, urinalysis, UACR, and kidney function come first. Clinician-directed autoimmune testing may be considered only when the overall pattern supports a specific inflammatory kidney question.
Use accurate office technique and, when appropriate, validated home or ambulatory monitoring. Blood work should not substitute for confirming that pressure is persistently high.
A clinician may use CBC, CMP or BMP, creatinine/eGFR, UACR, urinalysis, A1C or fasting glucose, a lipid panel, TSH, and an ECG. The exact combination depends on prior results, health conditions, pregnancy status, medicines, and the reason for testing.
A complete review may reveal a medication effect, a sleep-apnea pattern, or a reason for imaging that a laboratory order alone would miss.
Use the phenotype to guide the next step: ARR for primary aldosteronism, metanephrines for a catecholamine-type symptom pattern, thyroid testing for thyroid features, or focused kidney and autoimmune evaluation for abnormal urine and systemic clues.
Retesting depends on the original abnormality, medicine changes, treatment plan, and risk. UACR may need confirmation; potassium and creatinine may need reassessment after selected medication changes; glucose, lipids, thyroid markers, and aldosterone-related results follow different schedules.
A1C generally does not require fasting; a fasting glucose does. Lipid and hormone-test preparation can vary. Follow the instructions for the actual order rather than assuming every test has the same requirements.
Intense exercise, fever, infection, urinary or menstrual bleeding, dehydration, and acute illness can temporarily raise albumin excretion. An early-morning urine specimen is often useful when feasible, and an unexpected elevation may need confirmation.5
This is especially important for aldosterone and renin testing because several medication classes can shift the results. A clinician can decide whether an initial screen should be performed on current therapy or whether a safe medication strategy is needed.
Keep a current list of prescriptions, nonprescription medicines, vitamins, minerals, herbal products, and recent changes. Record home blood-pressure readings with dates and times so the laboratory pattern can be interpreted alongside the actual pressure pattern.
Most people with hypertension have no specific symptoms. Headache, fatigue, dizziness, and palpitations have many possible causes and should not be used to decide whether blood pressure is high.
| Symptom or pattern | What it may suggest | Related evaluation |
|---|---|---|
| Repeated high home or office readings | Sustained, white-coat, or masked hypertension | Validated home monitoring or ambulatory monitoring, plus focused baseline tests |
| Diabetes, abdominal adiposity, or family history of diabetes | Higher cardiometabolic and kidney risk | A1C or glucose, lipid panel, CMP or BMP, eGFR, and UACR |
| Foamy urine, blood in urine, swelling, or declining kidney function | Possible albuminuria, urinary abnormality, or kidney disease | Creatinine/eGFR, UACR, urinalysis, medication review, and clinician follow-up |
| Low potassium or difficult-to-control pressure | Medication effect, kidney disorder, or possible aldosterone excess | CMP or BMP and, when appropriate, aldosterone, renin, and ARR |
| Loud snoring, breathing pauses, daytime sleepiness | Possible obstructive sleep apnea | Sleep-focused assessment and sleep study |
| Episodic severe pressure with headache, sweating, tremor, or palpitations | Rare adrenal cause may need exclusion | Clinician-directed plasma free or 24-hour urinary fractionated metanephrines |
| Pregnancy or postpartum period with abnormal readings | Possible pregnancy-related hypertension or preeclampsia | Prompt obstetric or emergency assessment |
A reading above 180/120 mm Hg should be repeated after at least one minute. If it remains that high and is accompanied by chest pain, shortness of breath, back pain, weakness, numbness, vision change, difficulty speaking, or another new and concerning symptom, call 911 or local emergency services.9
Persistent readings in this range without emergency symptoms still require prompt contact with a healthcare professional. Abnormal blood pressure during pregnancy or after delivery also deserves prompt clinician-directed assessment rather than routine self-testing alone.
For a general interpretation framework, read How to Read and Understand Your Lab Results.
Ulta Lab Tests allows patients to order many relevant blood and urine tests online where available, review pricing, complete specimen collection through participating facilities, and receive results securely online. The guide to direct-access lab testing and what to expect explains the ordering, preparation, collection, and follow-up process.
Availability and ordering rules vary. Direct access does not mean every available test is necessary, and laboratory results cannot safely determine a diagnosis, medication change, or imaging plan without appropriate professional review.
Explore hypertension-related lab testing at Ulta Lab Tests.
No. Hypertension is established through accurate, repeated blood-pressure measurements, often supported by validated home or ambulatory monitoring. Blood and urine tests answer different questions: they can evaluate kidney effects, associated cardiometabolic risk, medication safety, electrolyte changes, and selected contributing conditions after a high-pressure pattern has been identified.
A common starting evaluation includes CBC; sodium, potassium, calcium, and creatinine with eGFR; fasting glucose or A1C; a lipid profile; and TSH. Urine testing commonly includes urinalysis and UACR. The exact combination depends on prior results, medicines, health conditions, pregnancy status, and the reason for testing.
Primary hypertension is the common, multifactorial form and usually does not have one identifiable laboratory cause. Secondary hypertension is driven by an identifiable condition, medicine, or substance. Recognizing a secondary pattern matters because it may change treatment, justify focused laboratory testing, or require a sleep study, imaging, or specialist evaluation.
Creatinine with eGFR, UACR, and urinalysis are complementary rather than interchangeable. eGFR estimates kidney filtration, UACR detects albumin leakage, and urinalysis looks for blood, protein, glucose, cells, and other urinary abnormalities. Reading them together can reveal kidney involvement that one marker alone might miss.
Yes. Albuminuria can be present while creatinine and eGFR still appear relatively preserved, especially earlier in some kidney-damage patterns. That is why UACR is not redundant with creatinine. An unexpected abnormal UACR may need confirmation because exercise, infection, fever, bleeding, dehydration, and acute illness can temporarily raise it.
Potassium can change with kidney function, dietary intake, gastrointestinal losses, supplements, and several blood-pressure medicines. A low level can be a clue to aldosterone excess, but normal potassium does not rule out primary aldosteronism. Potassium results should be interpreted with kidney function, medicines, and the reason for testing.
The 2025 Endocrine Society guideline conditionally suggests screening people with hypertension when appropriate testing and follow-up are feasible. Other guidance emphasizes resistant hypertension and selected higher-risk patterns. Because preparation and interpretation are complex, discuss the decision with a qualified clinician.
No. Obstructive sleep apnea generally requires a sleep-focused assessment and sleep study. Suspected renal artery narrowing may require targeted imaging. Blood and urine results can reveal associated cardiometabolic risk, kidney effects, or clues that justify further evaluation, but they cannot show breathing pauses during sleep or define renal artery anatomy.
It depends on the tests ordered. A1C generally does not require fasting, while a fasting glucose does. Lipid and hormone-test preparation can vary, and some results are sensitive to medicines, supplements, timing, posture, exercise, or collection conditions. Follow the instructions for the actual order rather than assuming one rule applies to every test.
No. Serum sodium reflects the relationship between sodium and body water and is tightly regulated by the body. A normal serum sodium result does not show that dietary sodium intake is appropriate, and a high or low result has many possible causes. Dietary assessment requires a different clinical approach.
Timing depends on the original result, medication changes, treatment plan, kidney function, and overall risk. UACR may be repeated to confirm albuminuria; creatinine and potassium may be checked after selected medication changes. Glucose, lipids, thyroid markers, and hormone tests follow different schedules, so use an individualized follow-up plan.
Hypertension is persistent elevation of blood pressure confirmed with accurate repeated measurements, not with a blood test. Blood and urine testing can help evaluate kidney filtration and damage, cardiometabolic risk, electrolyte and medication effects, and selected secondary causes after elevated pressure has been identified.
A blood-pressure cuff identifies the pressure problem. Hypertension lab tests investigate the health pattern around it. A focused evaluation often begins with kidney filtration, UACR, urinalysis, electrolytes, glucose regulation, lipids, CBC, and thyroid testing. More specialized testing should follow a specific clue.
Primary aldosteronism deserves particular attention because normal potassium does not exclude it and treatment can be mechanism-specific. Detailed screening and interpretation belong in the focused Primary Aldosteronism guide linked above.
Educational use only: This information is not a diagnosis or a substitute for professional medical advice. Seek emergency care for severe blood pressure accompanied by concerning symptoms, and seek prompt obstetric care for abnormal blood pressure during pregnancy or after delivery.
Commercial disclosure: Ulta Lab Tests offers direct-access laboratory testing where available and may receive revenue when tests are purchased through its website. Test availability and ordering requirements vary by location.
Originally published July 26, 2026. Updated August 28, 2026.
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