Endothelial dysfunction testing

What Is Endothelial Dysfunction? The Warning Your Arteries Send

Endothelial dysfunction is the failure of the blood vessel lining to make enough nitric oxide to widen small arteries when tissue needs more blood. It shows up as pain after meals, rising blood pressure or erection problems, and it is tested by measuring arterial stiffness and endothelial function, not by a cholesterol panel.

Your blood vessels have a lining that decides, moment to moment, whether they can open. When it falters, the first complaints often come from organs nobody thinks to connect.

What is endothelial dysfunction? It is the failure of the thin lining inside your blood vessels, the endothelium, to make enough nitric oxide to let small arteries widen when a tissue needs more blood. It rarely announces itself as a heart problem. It tends to show up as separate complaints that get sent to separate specialists. The video above, Your Gut Is Suffocating, tells that story from Chapter 9 of The Angry Gut by Dr. Gurpreet Singh Padda, MD, MBA, MHP, and Ami Michelle Grimes. Here the focus is measurement: what a routine visit checks, what it leaves out, and which tests show how your vessels actually behave.

What is endothelial dysfunction? One lining, many complaints

Eating is a demand on your circulation. Blood flow to the bowel rises by 30-150% after a meal, so an artery that manages fine while you sit still may not keep up with lunch. An erection is a nitric oxide event in a small artery. Blood pressure depends on how easily vessels relax. When the lining falters, each of those can fail on its own schedule and be handled on its own: pain after lunch goes to gastroenterology, erection problems to urology, blood pressure to cardiology. Three offices, one vessel lining.

Your gut is the first brain, and the second brain sits in your skull. The first brain is fed from behind its lining, and the tips of the tiny absorbing fronds called villi sit at the far end of that supply line. When blood runs short, that is where the shortfall lands first, and tissue that is not getting blood cannot heal well.

What causes endothelial dysfunction?

Two biological routes matter most. The enzyme that makes nitric oxide needs raw materials, and when they run low it uncouples and produces superoxide, a corrosive radical, so the machinery built to open vessels starts damaging them. Oxidized LDL, cholesterol-carrying particles that have gone rancid, binds a receptor on the vessel lining and sets off the same chemistry. In 4,658 people followed for nearly twenty years, those with the highest circulating levels of that receptor had 1.76 times the risk of a first heart attack.

There is also a backup route most people never hear about. Nitrate from green leafy vegetables is concentrated into saliva, and bacteria at the back of your tongue turn it into nitrite, which the body can use to make nitric oxide. When 19 healthy volunteers used antiseptic mouthwash for seven days, nitrite production in the mouth dropped by 90% and blood pressure rose by 2-3.5 mmHg. In one cohort, rinsing twice a day or more went with 1.85 times the rate of new high blood pressure. The effect shows up mainly in older adults and people already treated for hypertension, whose main enzyme is already struggling.

Then there is the economic driver. Frying oil is cheapest at the end of its life, reused in fryers that are changed least often, and the people with the fewest food choices eat the most of it. The blood tests behind reassuring vegetable oil studies read an intact fatty acid, drawn once, and cannot see what oxidized before it was swallowed. Are seed oils bad for you covers that measurement gap.

Does a routine checkup test for endothelial dysfunction?

A standard visit measures blood pressure at the arm and orders a cholesterol panel. Both are useful, and neither tells you whether your vessel lining can open on demand. A scope looks at the inside surface of the gut and cannot see the arteries feeding it from behind. The man at the center of the video had four scopes before anyone imaged an artery. He also had a normal body weight, and the European guideline now names the expectation of a thin, wasted patient as a pitfall that delays diagnosis.

Erection problems are the most overlooked signal of all. Pooling 14 studies with 92,757 men, erectile dysfunction predicted heart attack at 1.62 times the usual risk. Among men with coronary disease who had both conditions, the sexual symptom came first in 93% of them, by about two years. It is usually answered with a prescription and no further questions. The medicine works. The silence after it is the problem.

How is endothelial dysfunction tested?

Measura [Cardiometabolic and Autonomic Health Analysis] does not image the arteries that supply your intestines. If meals reliably bring pain, or you have started eating less to avoid it, imaging of those mesenteric arteries is a separate test done elsewhere, and your physician needs to hear about the pattern. What Measura can show is how the vessels you share with the rest of your body are behaving:

• Arterial stiffness and endothelial function measures how stiff your larger arteries are and how well the vessel lining lets them widen.
• Pulse volume recording records the pulse waveform at several points along your arms and legs to show how blood moves through those arteries.
• Ankle-brachial index sets the pressure reading taken at your ankle against the one taken at your arm, a simple screen for narrowing in the legs.
• Laboratory panels cover blood work on glucose, insulin and lipids, the metabolic conditions that wear on the vessel lining.

A normal result does not rule out a narrowed gut artery, and an abnormal one does not diagnose a disease by itself. Findings go to your physician, who decides what needs imaging or treatment. Why a normal ankle-brachial index can be misleading explains one of those limits.

What to ask for

• If pain reliably follows meals, ask whether anyone has looked at the arteries, not just the lining of the gut.
• If you have erection problems, tell your primary care physician, not only the doctor who wrote the prescription.
• If you use antiseptic mouthwash twice a day, ask your dentist what it is treating and when the course should end.
• If your blood pressure keeps climbing, ask whether a vascular measurement would add to the arm cuff reading.

Do not change any medication on your own; bring these questions to the physician who prescribed it. Dr. Padda was trained, like every physician, to send each complaint to the organ that reports it, and the humbling lesson of this case is that the gut could not be rescued from inside the gut. The Chapter 9 book companion page carries every study with its full numbers, and finding cardiovascular risk early explains how vascular testing fits a checkup. Before the vessel wall itself stiffens, high glucose strips the thin sugar coat that lines it, described in the endothelial glycocalyx.

Frequently asked questions

What are the symptoms of endothelial dysfunction?

There is no single symptom. The lining fails quietly, and the first complaints come from whichever tissue has the least reserve: pain after meals, erection problems, blood pressure that keeps rising, or legs that tire when you walk. Because each goes to a different specialist, the shared cause is easy to miss. Leg symptoms and circulation covers the limb side.

Can mouthwash raise blood pressure?

An antiseptic rinse wipes out the bacteria on the back of your tongue that convert nitrate from vegetables into nitrite. Among healthy volunteers, seven days of rinsing cut oral nitrite production by 90% and raised blood pressure by a few points, and twice-daily use tracked with new hypertension in a cohort. A short course for a dental problem is different from years of habit. Questions worth asking your doctor helps you raise it.

Is erectile dysfunction a sign of heart disease?

It often comes first. Pooled studies link erectile dysfunction to later heart attacks, and among men already diagnosed with coronary disease, most noticed the erection problem roughly two years before any chest symptoms. It reflects how well small arteries open, which is why it deserves a cardiovascular question and not only a prescription. Who should have cardiometabolic testing explains who benefits.

Can Measura find a blocked artery to my intestines?

No. Measura does not image the mesenteric arteries that feed the gut; that is a separate imaging test your physician can arrange. Measura measures how your larger arteries stiffen and open, how blood moves through your limbs, and the metabolic blood work behind vessel health, which describes the terrain your gut shares with the rest of you. What to expect at your appointment describes the visit.

Does a normal cholesterol panel mean my arteries are healthy?

Not necessarily. A cholesterol panel describes fat-carrying particles in your blood, not whether your vessel lining can widen when tissue needs more blood. People with normal cholesterol can still have stiff arteries or a struggling endothelium, especially with high insulin or rising blood pressure. Measuring the vessel directly answers a different question. What insulin resistance looks like before diabetes explains one hidden driver.

What damages the lining of your blood vessels?

Two routes matter most. When the enzyme that makes nitric oxide runs short of raw materials, it produces superoxide, a corrosive radical, so the machinery built to open vessels starts damaging them. Oxidized LDL, cholesterol-carrying particles that have gone rancid, binds a receptor on the lining and sets off the same chemistry. Reused frying oil is the economic driver: cheapest, eaten most where food choices are fewest, and invisible to standard blood tests.

What foods help your blood vessels make nitric oxide?

Green leafy vegetables supply a backup route. Their nitrate is concentrated into saliva, and bacteria at the back of your tongue turn it into nitrite, which the body can use to make nitric oxide. That route matters most for older adults and people already treated for high blood pressure. Antiseptic mouthwash wipes out those bacteria, so a twice-daily rinse habit can undercut the vegetables on your plate.

References

• Terlouw, L. G., Moelker, A., Abrahamsen, J., Acosta, S., Bakker, O. J., Baumgartner, I., Boyer, L., Corcos, O., van Dijk, L. J., Duran, M., Geelkerken, R. H., Illuminati, G., Jackson, R. W., Kärkkäinen, J. M., Kolkman, J. J., Lönn, L., Mazzei, M. A., Nuzzo, A., Pecoraro, F., … Bruno, M. J. (2020). European guidelines on chronic mesenteric ischaemia – joint United European Gastroenterology, European Association for Gastroenterology, Endoscopy and Nutrition, European Society of Gastrointestinal and Abdominal Radiology, Netherlands Association of Hepatogastroenterologists, Hellenic Society of Gastroenterology, Cardiovascular and Interventional Radiological Society of Europe, and Dutch Mesenteric Ischemia Study group clinical guidelines on the diagnosis and treatment of patients with chronic mesenteric ischaemia. United European Gastroenterology Journal, 8(4), 371-395. https://doi.org/10.1177/2050640620916681
• Janaszak-Jasiecka, A., Siekierzycka, A., Płoska, A., Dobrucki, I. T., & Kalinowski, L. (2021). Endothelial dysfunction driven by hypoxia—The influence of oxygen deficiency on NO bioavailability. Biomolecules, 11(7), 982. https://doi.org/10.3390/biom11070982
• Schiopu, A., Björkbacka, H., Narasimhan, G., Loong, B. J., Engström, G., Melander, O., Orho-Melander, M., & Nilsson, J. (2023). Elevated soluble LOX-1 predicts risk of first-time myocardial infarction. Annals of Medicine, 55(2), 2296552. https://doi.org/10.1080/07853890.2023.2296552
• Kapil, V., Haydar, S. M., Pearl, V., Lundberg, J. O., Weitzberg, E., & Ahluwalia, A. (2013). Physiological role for nitrate-reducing oral bacteria in blood pressure control. Free Radical Biology & Medicine, 55, 93-100. https://doi.org/10.1016/j.freeradbiomed.2012.11.013
• Joshipura, K., Muñoz-Torres, F., Fernández-Santiago, J., Patel, R. P., & Lopez-Candales, A. (2020). Over-the-counter mouthwash use, nitric oxide and hypertension risk. Blood Pressure, 29(2), 103-112. https://doi.org/10.1080/08037051.2019.1680270
• Vlachopoulos, C. V., Terentes-Printzios, D. G., Ioakeimidis, N. K., Aznaouridis, K. A., & Stefanadis, C. I. (2013). Prediction of cardiovascular events and all-cause mortality with erectile dysfunction: A systematic review and meta-analysis of cohort studies. Circulation: Cardiovascular Quality and Outcomes, 6(1), 99-109. https://doi.org/10.1161/CIRCOUTCOMES.112.966903
• Montorsi, P., Ravagnani, P. M., Galli, S., Rotatori, F., Veglia, F., Briganti, A., Salonia, A., Dehò, F., Rigatti, P., Montorsi, F., & Fiorentini, C. (2006). Association between erectile dysfunction and coronary artery disease. Role of coronary clinical presentation and extent of coronary vessels involvement: The COBRA trial. European Heart Journal, 27(22), 2632-2639. https://doi.org/10.1093/eurheartj/ehl142
• Marklund, M., Wu, J. H. Y., Imamura, F., Del Gobbo, L. C., Fretts, A., de Goede, J., Shi, P., Tintle, N., Wennberg, M., Aslibekyan, S., Chen, T. A., de Oliveira Otto, M. C., Hirakawa, Y., Eriksen, H. H., Kröger, J., Laguzzi, F., Lankinen, M., Murphy, R. A., Prem, K., … Risérus, U. (2019). Biomarkers of dietary omega-6 fatty acids and incident cardiovascular disease and mortality: An individual-level pooled analysis of 30 cohort studies. Circulation, 139(21), 2422-2436. https://doi.org/10.1161/CIRCULATIONAHA.118.038908

Related reading

• Are Seed Oils Bad for You? What Your Numbers Can Actually Show
• What Does Low Vitamin D Mean? Reading the Number on Your Report
• Arterial Stiffness and Endothelial Function

Medically reviewed by Dr. Gurpreet Singh Padda, MD, MBA, MHP, medical director of Measura. Last reviewed September 12, 2026.