Home
/

Hypertension

REVIEWED BY
Bill Maish, MD
Clinical Content Consultant
Published
May 30, 2026
Last updated
May 30, 2026
Key takeaway:

Blood testing for hypertension measures sodium (135–145 mEq/L) and potassium (3.5–5.0 mEq/L), the two electrolytes that directly regulate fluid volume and vascular tone via the renin–angiotensin–aldosterone system. Potassium in the mid-to-upper normal range relaxes vessels and counterbalances aldosterone-driven sodium retention, while low potassium raises suspicion for primary aldosteronism. Tracking these electrolytes identifies secondary causes of hypertension and is associated with risks of arrhythmia and stroke.

Read more →
Table of contents

Hypertension and the Blood Markers Behind Pressure Control

Hypertension biomarkers are blood-borne signals that mirror the body’s pressure-control systems and the strain high pressure puts on organs. They come from the kidneys, blood vessels, heart, and nervous system, and together they trace why blood pressure is elevated and how it is affecting tissues. Key signals of salt and water regulation (renin, angiotensin II, aldosterone) reveal the activity of the renin–angiotensin–aldosterone system, while heart-stretch proteins (BNP, NT‑proBNP) reflect cardiac wall stress. Markers of vessel health and inflammation (endothelin‑1, nitric oxide pathway surrogates, C‑reactive protein) point to endothelial dysfunction, and measures of kidney filtration reserve (creatinine, cystatin C) show renal involvement. Signals of sympathetic drive (plasma metanephrines) can uncover adrenal or nerve-mediated pressure surges. Testing these biomarkers helps differentiate primary from secondary causes, estimates target-organ impact, and supports more precise treatment choices by aligning therapy with the dominant pathway driving an individual’s hypertension.

Why Blood Work Matters in High Blood Pressure

Blood testing in hypertension reveals how the kidneys, adrenal hormones, and blood vessels are managing volume and vascular tone. Sodium and potassium are the frontline signals of the renin–angiotensin–aldosterone system, the same network that drives long-term blood pressure and impacts heart, brain, and kidney health.Sodium is typically 135–145, and the healthiest physiology tends to keep it in the middle of that range. Importantly, serum sodium reflects water balance rather than “saltiness” of the diet. Potassium is usually 3.5–5.0, with cardiovascular benefits often seen when it sits in the mid-to-upper normal range because potassium relaxes vessels and counterbalances aldosterone-driven sodium retention. High sodium in blood often means relative dehydration; high potassium can appear with kidney impairment or medications that suppress aldosterone, and can disturb heart rhythm.When values drop, they tell a specific story. Low sodium usually reflects excess water relative to sodium from diuretics, heart or kidney dysfunction, or hormone disorders; in people with hypertension it can signal over-diuresis or advanced cardiac/renal disease, with headache, nausea, confusion, or seizures when severe—older adults and women on thiazides are especially susceptible. Low potassium suggests renal losses or aldosterone excess; in hypertension it raises suspicion for primary aldosteronism, and it can worsen blood pressure by tightening vessels and promoting sodium retention, causing weakness, cramps, palpitations, or arrhythmias. Teens on stimulants and pregnant patients with vomiting may also trend low.Big picture: electrolytes knit together vascular tone, kidney filtration, and adrenal signaling. Tracking them helps identify secondary causes of hypertension, monitor medication effects, and anticipate long-term risks like stroke, arrhythmia, and chronic kidney disease.

Why Electrolytes Are Only Part of the Pressure Story

Hypertension blood testing provides a window into how your body manages blood pressure, a key factor in the health of your heart, blood vessels, brain, kidneys, and other organs. High blood pressure can silently strain these systems, affecting everything from energy and metabolism to cognition and immune function. At Superpower, we focus on two essential electrolytes—sodium and potassium—because they play central roles in blood pressure regulation and overall cardiovascular stability.Sodium is a mineral that helps control fluid balance and nerve signaling. When sodium levels are too high, the body tends to retain water, which can increase blood volume and raise blood pressure. Potassium, on the other hand, helps relax blood vessel walls and supports the excretion of excess sodium through the kidneys. The balance between sodium and potassium is crucial: too much sodium or too little potassium can tip the system toward hypertension.Healthy sodium and potassium levels support stable blood pressure, protect blood vessel integrity, and help maintain the delicate balance of fluids inside and outside your cells. This balance is vital for the heart’s ability to pump efficiently and for the kidneys to filter blood properly, both of which are essential for long-term cardiovascular health.Interpretation of sodium and potassium results can be influenced by factors such as age, pregnancy, acute or chronic illness, certain medications (like diuretics or steroids), and laboratory assay differences. These factors should be considered when evaluating your results.

FAQs

It checks how high blood pressure is affecting your body’s fluid, kidney, and hormone balance. Superpower tests your blood for sodium and potassium, the core electrolytes that shape blood volume and vessel tone (Na+, K+). Patterns in these markers can point to kidney strain, diuretic effects, or hormone-driven causes of high blood pressure (renin–angiotensin–aldosterone system).

Because blood pressure is tightly linked to kidney function and hormone signaling. Electrolytes show whether your system is holding too much fluid, losing minerals, or being pushed by aldosterone-driven effects. Identifying these shifts early helps explain resistant readings and flags secondary causes or medication effects before complications develop.

Yes. With Superpower, our team member can organise a blood draw in your home.

Start with a baseline at diagnosis. Recheck after starting or changing medicines that affect electrolytes (diuretics, ACE inhibitors, ARBs, MRAs). If stable, monitor periodically; timing varies by kidney function, medications, and control of blood pressure, often every 3–12 months. More frequent checks are needed if results are abnormal or symptoms develop.

Salt and potassium intake, hydration status, vomiting/diarrhea, strenuous exercise, and heat/sweating shift electrolytes. Medicines such as diuretics, ACE inhibitors/ARBs, MRAs, laxatives, and steroids change sodium/potassium balance. Kidney disease and aldosterone/cortisol disorders alter levels. Sample issues like hemolysis can falsely raise potassium.

Fasting isn’t required. Stay normally hydrated, avoid unusually salty meals or high-dose potassium supplements the day before, and skip intense exercise right before the draw. Take your medications as prescribed unless you were specifically told otherwise. Let us know about all drugs and supplements that can affect electrolytes.

References

  1. Whelton, P. K., Carey, R. M., Aronow, W. S., Casey, D. E., Collins, K. J., Dennison Himmelfarb, C., DePalma, S. M., Gidding, S., Jamerson, K. A., Jones, D. W., MacLaughlin, E. J., Muntner, P., Ovbiagele, B., Smith, S. C., Spencer, C. C., Stafford, R. S., Taler, S. J., Thomas, R. J., Williams, K. A., ... Wright, J. T. (2018). 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults. Hypertension, 71(6), e13-e115. https://doi.org/10.1161/HYP.0000000000000065
  2. Mente, A., O'Donnell, M. J., Rangarajan, S., McQueen, M. J., Poirier, P., Wielgosz, A., Morrison, H., Li, W., Wang, X., Di, C., Mony, P., Devanath, A., Rosengren, A., Oguz, A., Zatonska, K., Yusufali, A. H., Lopez-Jaramillo, P., Avezum, A., Ismail, N., ... Yusuf, S. (2014). Association of urinary sodium and potassium excretion with blood pressure. The New England Journal of Medicine, 371(7), 601-611. https://doi.org/10.1056/NEJMoa1311989
  3. Funder, J. W., Carey, R. M., Mantero, F., Murad, M. H., Reincke, M., Shibata, H., Stowasser, M., & Young, W. F. (2016). The management of primary aldosteronism: Case detection, diagnosis, and treatment: An Endocrine Society clinical practice guideline. The Journal of Clinical Endocrinology & Metabolism, 101(5), 1889-1916. https://doi.org/10.1210/jc.2015-4061
  4. Seay, N. W., Lehrich, R. W., & Greenberg, A. (2020). Diagnosis and management of disorders of body tonicity-hyponatremia and hypernatremia: Core Curriculum 2020. American Journal of Kidney Diseases, 75(2), 272-286. https://doi.org/10.1053/j.ajkd.2019.07.014
  5. Palmer, B. F., & Clegg, D. J. (2019). Physiology and pathophysiology of potassium homeostasis: Core Curriculum 2019. American Journal of Kidney Diseases, 74(5), 682-695. https://doi.org/10.1053/j.ajkd.2019.03.427

Built by the world’s top doctors and scientists

Dr Anant Vinjamoori, MD

Chief Longevity Officer, Superpower

Board-certified longevity physician. Previously product leader at Virta Health & CMO at Modern Age. Featured in  WSJ, Forbes, and Fortune.

Learn more

Dr Leigh Erin Connealy, MD

Clinician & Founder of The Centre for New Medicine

Leads the largest integrative medical clinic in North America. A pioneer in integrative oncology.

Learn more

Dr Robert Lufkin

UCLA Medical Professor, NYT Bestselling Author

A leading voice on metabolic health and longevity as shown in The Today Show, USA Today and FOX.

Learn more

Dr Abe Malkin

Founder & Medical Director of Concierge MD

Leads a nationwide medical practice, and Drip Hydration, a mobile IV therapeutics company

Learn more
Membership slide 1
Membership slide 1
Membership slide 2
Membership slide 3
1 / 3

Your membership starts here

Annual 100+ biomarker panel

Data dashboard and digital twin

Upload past labs and connect wearables

Personalized health protocol

24/7 care team access

AI companion for all health questions

Marketplace with additional solutions

$199

/year*

Billed annually

HSA/ FSA eligible
Cancel anytime
Results in a week

* Pricing may vary for members in New York and New Jersey