High blood pressure and kidneys
When you look at the connection between high blood pressure and the kidneys, the kidneys are often both the cause and the victim. That means they can both cause high blood pressure and be damaged by it, with the latter being much more common. Over time, the damage caused by high blood pressure often makes the kidney a co-conspirator.
The kidney as a cause
Why exactly kidney diseases can lead to high blood pressure isn't yet fully understood and is still being researched. We do know that certain kidney diseases trigger high blood pressure. For example, narrowing of one or both renal arteries or inflammation of both kidneys can very quickly lead to high blood pressure. People with a shrunken kidney on one side or polycystic kidney disease also often have high blood pressure. If the kidneys have been damaged by long-standing diabetes, this also often leads to high blood pressure.
The cause may be a hormonal imbalance resulting from kidney damage. In addition to neural (nerve-mediated) regulatory circuits, the kidneys also control hormonal regulatory circuits that affect blood pressure. When kidney function declines, more blood-pressure-raising hormones are released. These in turn cause the nerves to constrict the blood vessels, which raises blood pressure.
However, the sometimes severely impaired excretion of water and salt associated with reduced kidney function may also play a role in causing kidney-related high blood pressure.
However, the sometimes severely impaired excretion of water and salt associated with reduced kidney function may also play a role in causing kidney-related high blood pressure.
To find out whether the kidney is causing the high blood pressure, doctors look at an ultrasound of the kidneys, certain blood tests, and a urine test for protein and blood components.
The kidney as a victim
However, the kidney is much more often the victim than the cause of excessively high blood pressure. The damage that high blood pressure causes to blood vessels often affects the vessels in the kidneys too. If the kidney vessels are narrowed by atherosclerosis, which can be caused by persistently high pressure, or by inflammation, clots, or the nerve-related constriction mentioned above, higher blood pressure is needed to ensure sufficient blood flow to the kidneys. The smallest capillaries, which are part of the kidney's filtering system, suffer the most. They harden, become porous, and are increasingly unable to perform their filtering function. The larger renal arteries can also calcify, thereby restricting blood flow. This paves the way for chronic kidney failure.
Because the kidneys are directly involved in regulating blood pressure (see above), a vicious circle develops. High blood pressure damages the kidneys, and the kidneys try to keep blood flow high enough to maintain filtering function by releasing more hormones, which in turn raise blood pressure further.
Because kidney damage, like high blood pressure, does not cause any symptoms in its early stages, it often goes undetected or is only discovered once the organ has already suffered more severe damage.
People with high blood pressure are therefore considered the kidney patients of tomorrow and should always have their kidney function checked as well. Conversely, it is also important for kidney patients to keep an eye on their blood pressure.
People with high blood pressure are therefore considered the kidney patients of tomorrow and should always have their kidney function checked as well. Conversely, it is also important for kidney patients to keep an eye on their blood pressure.
Extensive information about chronic kidney disease, including stages and a calculator, can be found at https://nierenrechner.de/
More information about kidneys is available from the German Kidney Association (Bundesverband Niere e. V.) - http://www.bnev.de/ - or PKD Familial Cystic Kidney Disease e. V. - http://www.pkdcure.de/.
Renal denervation (RDN)
For treating severe high blood pressure that cannot be controlled or adequately controlled with medication, there is a minimally invasive option. This relatively new treatment is called renal denervation or denervation (RDN). A catheter is inserted through the femoral artery, as in a cardiac catheterization, and certain spots in the renal artery are ablated. This targeted interruption of the nerve signals stops the vicious circle: reduced kidney blood flow causes continuous peripheral activation of the sympathetic nervous system and thus high blood pressure.
The procedure itself is not new. Until the 1950s, complete cutting of the sympathetic nerve below the diaphragm was used as a last-resort treatment for high blood pressure. This relatively extensive and complex procedure usually achieved the desired reduction in blood pressure but, unlike the new method, also caused many side effects.
A study published in April 2022 showed a good reduction in blood pressure from renal denervation when used together with antihypertensive medication.
Sources:
- https://www.dgfn.eu/hintergrundmaterial.html
- https://www.gesundheit.de/krankheiten/gefaesserkrankungen/bluthochdruck-hypertonie/bluthochdruck-schaedigt-die-nieren
- https://www.hochdruckliga.de/nachricht/interventionelle-verfahren-zur-blutdrucksenkung-wo-stehen-wir-heute
- https://www.pharmazeutische-zeitung.de/index.php?id=75567
- www.thelancet.com/journals/lancet/article/PIIS0140-6736(22)00455-X/fulltext
- https://www.medical-tribune.de/medizin-und-forschung/artikel/entnervte-niere-laesst-den-druck-sinken
- https://pubmed.ncbi.nlm.nih.gov/35029703/
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.
