Effects of high blood pressure on the blood vessels
Blood is pumped by the heart through "pipes" to even the most remote corners of the body. These pipes are called blood vessels. They are divided into arteries and veins. Arteries are the blood vessels that carry oxygen-rich blood from the heart to its destination. They are subjected to more strain from the pressure generated by the heart as a pump than veins are. Veins carry the blood that has "unloaded" nutrients and oxygen at its destination (and is therefore now low in oxygen) back to the heart.
Without a certain amount of pressure, the circulatory system cannot function - so we need pressure to live.Our blood vessels, both arteries and veins, have a similar structure. Both are made up of three layers:
- The innermost layer ensures an optimal exchange of nutrients and oxygen between the blood and the vessel wall. It consists of flat cells (endothelium) and connective tissue.
- The middle layer consists of smooth muscle cells, collagen fibers, and elastic fibers. It regulates the diameter of the vessel through muscle contractions.
- The outermost layer consists of elastic networks formed by collagen fibers. It forms the vessel's outer boundary, anchors it in the surrounding tissue, and contains nerves and blood vessels that supply it.
Arteries are structurally stronger and thicker than veins. Veins have thinner walls and can stretch more easily than arteries. Some veins have valves that prevent blood from flowing back into the limbs. This helps the blood return to the heart.
Blood pressure mainly affects the arteries. They can withstand the heart's pressure because especially the arteries near the heart can expand elastically and, during the heart's relaxation phase, compensate for the drop in pressure by contracting.
Blood pressure mainly affects the arteries. They can withstand the heart's pressure because especially the arteries near the heart can expand elastically and, during the heart's relaxation phase, compensate for the drop in pressure by contracting.
However, if persistently high blood pressure puts strain on the arteries, they become damaged. Bulges known as aneurysms can form, especially in the aorta, which is closest to the heart. In such cases, the vessel wall can no longer withstand the pressure and expands. Because the vessel wall no longer has its normal strength at these points, the risk of the vessel tearing there is greatly increased.
There are different types of aneurysms: saccular, fusiform, dissecting (the vessel wall is split - bleeding occurs between the wall layers), and pseudoaneurysms. In a pseudoaneurysm, a blunt or penetrating injury causes a tear in the vessel wall. The surrounding tissue can contain the resulting hematoma and thus delay fatal blood loss when a large artery is injured. However, this usually only works for a short time. Because this "aneurysm" forms outside the vessel wall, it is called falsum or spurium.
However, small injuries can also form in the innermost layer of the arteries. This can cause blood fats (for example, cholesterol) and inflammatory cells to get stuck and form so-called plaques. This is an ongoing process that progressively narrows the blood vessel and restricts blood flow. The vessel loses its elasticity and hardens (arteriosclerosis). It loses the ability to compensate for changing pressure conditions, and blood pressure therefore rises. As the condition progresses, plaques covered only by a thin endothelial layer can break through this layer into the interior of the vessel. To repair this, platelets immediately accumulate at that spot. This is similar to an external wound on which a scab forms and closes the wound. The same thing now happens inside the vessel: the platelets clump together and form a thrombus (blood clot). If the vessel is already severely narrowed by arteriosclerosis or the thrombus is large enough, it can completely block the vessel. However, it can also break loose, get stuck at a narrowing elsewhere, and block the vessel there.
As a result, the area supplied by the vessels downstream of the blockage no longer receives blood.
Depending on where in the body this happens, the blockage can lead to serious consequences such as a heart attack, stroke, kidney failure, and similar conditions.
Depending on where in the body this happens, the blockage can lead to serious consequences such as a heart attack, stroke, kidney failure, and similar conditions.
Sources:
This article is from Tensana – the leading app since 2011, helping hundreds of thousands of people monitor their blood pressure every day.
Our content is based on carefully researched, evidence-based data and is continuously updated (as of 11/2025).
Author Sabine Croci is a qualified medical assistant with many years of experience in internal medicine and cardiology practices as well as outpatient care, and has headed the specialist editorial team at Tensana since 2015. Thanks to her extensive additional qualifications as an emergency medical technician, first responder, and in various areas of therapy and emergency care, she provides well-founded, practical, and reliably verified information.
Author Sabine Croci is a qualified medical assistant with many years of experience in internal medicine and cardiology practices as well as outpatient care, and has headed the specialist editorial team at Tensana since 2015. Thanks to her extensive additional qualifications as an emergency medical technician, first responder, and in various areas of therapy and emergency care, she provides well-founded, practical, and reliably verified information.
