Perspectives · Physiology

Vascular health: what holds the blood

Our vascular health could be called our most precious asset — the vast network of vessels that lets our life blood reach every corner of the body.

By Dr Cindy de Villiers · Combined from two posts, 2020–2021 · Reviewed and edited July 2026 · General information, not medical advice

If our blood vessels are damaged sufficiently, our blood leaves us — as if the soul had trickled out, leaving a heap of tissue and bone. It is little wonder the ancient traditions equated blood with the life force. Yet we tend to think of the vessels themselves as mere plumbing. They are anything but.

More than tubes

Blood vessels are far more than flexible tubes carrying blood to the organs. They play an integral part in sensing what is happening in the body, and in responding to it. They must respond to an almost infinite range of conditions: nutritional status (is there enough magnesium?), microbial (are there bacteria or viruses in the blood?), toxins (is a heavy metal present?), and the biomechanical environment — the pumping of the heart, the turbulence of the blood, the structure of the fluid in direct contact with the vessel wall. And they respond in essentially three ways: through inflammation, through oxidative stress, and by adjusting the immune response. A continuous process of damage, repair, sensing, and responding is happening every millisecond.

Sound familiar? The cells lining the vessels — the endothelium — react to their environment just like any other tissue. What makes them so critical is that every other tissue relies on them. The endothelium helps produce signalling gases such as nitric oxide that support healthy blood flow. These days we are much less likely to die from blood loss: we have better ways to stem it, prevent it, and even to borrow someone else's blood as a stop-gap. What we may be missing is that vascular health matters more than ever.

Hardening of the arteries

What happens when the whole system — from damage through to response — is either overwhelmed or under-resourced? The dreaded “hardening of the arteries,” or atherosclerosis.

Think of us going about our business, repeatedly throwing insults at the body — junk food, sugar, alcohol — while withholding the things the vessels need to repair, such as good sleep, movement, and nutrients. The vessels sense danger and use whatever is available to patch the damage, signalling the rest of the body to raise inflammation, oxidative stress, and immune activity. Layer upon layer of poorly healed tissue builds up. Blood flow is compromised, and further inflammation and repair are stimulated. Then we wonder why, all of a sudden, a critical artery in the heart is overwhelmed and a heart attack occurs. The vessels supplying the heart are especially exposed to biomechanical force, and this is often where poor vascular health first shows. Cardiovascular disease remains a leading cause of death, particularly in older age. Where it does not present so dramatically, the general decline in blood flow — and the associated inflammation — quietly slows the muscles, gut, lungs, heart, and brain.

For longevity and an enjoyable life, we want our vascular health.

Assessing vascular health

So how is vascular health assessed? There are now numerous direct and indirect methods, each with a slightly different emphasis, and many of the newer devices have been slow to reach New Zealand. The clinic uses a combination of approaches to build a picture — including ambulatory blood pressure monitoring, Holter monitoring, and event monitoring, all of which can be done in a person's own home.

The clinic also uses a device called a SphygmoCor. Rather than assessing pressure in the arm, it estimates the pressure at the aorta — the large artery leaving the heart — which is a more relevant reading than the pressure measured at the arm. It also assesses the stiffness of the aorta and can calculate a “vascular age.” The assessment is straightforward: the person sits in a chair while a cuff on the arm inflates several times, and the results are available immediately. Used alongside history, examination, and other investigations, it is one more way of understanding an individual's cardiovascular picture — not a diagnosis in itself, and not a substitute for clinical assessment.

What holds the blood

Returning to an earlier essay on the vagus nerve and heart rate variability: the health of our blood vessels is entwined with the whole of us, and is reflected in HRV. Heart rate variability is a reflection of life. Protecting our vessels protects not only our bodies, but something of the life force itself.