The point is that, in one way or another, these two organs depend on each other . The medical community has long noted a link between heart and kidney health, so if one is affected, it appears the other is as well. That is, a heart problem can lead to kidney disease, and a failing kidney can increase the risk of heart disease.
How is this possible? you will ask. Well, to understand this better, we must know its functions.
Functions of the kidneys and heart
For one thing, the kidneys are two bean-shaped organs that are about the size of a fist. They are located on either side of the spine, just below the rib cage. As a curiosity, they are not at the same level, the right kidney is a little lower, being pushed by the liver.
What comes to mind for many when we talk about the kidney is that its function is to filter. And it is true that this is one of its functions, but the kidney does many more things (and very important!). The kidneys are biochemical mini-factories that perform functions such as: remove waste products and excess water from the blood, help control blood pressure, and maintain bone health and strength. In addition, they contribute to the production of red blood cells and maintain a healthy mineral balance in the blood (such as sodium, phosphorus and potassium).
On the other hand, the heart is an organ mainly composed of muscle , of a size similar to that of the kidneys, which is protected by the rib cage, right in the middle of the two lungs, with the lower point slightly inclined to the left side . (It’s not that the heart is on the left side of the body, it’s that its tip is oriented to the left and, if we divide the body in half, it seems that “there is more heart” on the left side).
It is the organ responsible for pumping oxygen-rich blood throughout the body, which keeps the cells, organs and systems of our body alive. The heart, together with the blood vessels and the blood they transport, constitute the “cardiovascular system” , which is the distribution mechanism that moves blood from the heart to the rest of the organs, thus transporting oxygen and nutrients, while collecting waste materials for the body to eliminate.
Heart and kidney diseases
Kidney disease can be described as the damage and inability of the kidneys to filter waste products from the blood as effectively as they should or directly a significant decrease in the amount of urine (known as oliguria). When we talk about chronic kidney disease, we are referring to one in which kidney function has progressively worsened over time and has already established itself as a disease of long evolution and duration.
Meanwhile, heart disease can be characterized by any problem that prevents the heart from pumping blood as effectively as it should. Among the problems of the heart and blood vessels, it is worth highlighting the accumulation of cholesterol (mainly of the LDL type, for this reason it is known as “bad cholesterol”), cells and other elements in the walls of the arteries, such as blood clots ( thrombi). These, in the end, are mechanisms that obstruct the normal blood flow and, therefore, that prevent the nutrition of the tissues of our body. This includes both the kidneys or the liver, as well as the heart itself. The effects can vary greatly, depending on the affected blood vessel.
When an artery becomes blocked and the organs behind that artery cannot be nourished, those tissues begin to die. This is what is known as a heart attack, if it occurs due to a thrombus in the lungs, it is a pulmonary thromboembolism, in the case of the brain, an ischemic stroke, and if it occurs in the arteries of the heart, it is a myocardial infarction, and So with the rest of the organs.
Understand the relationship between the heart and the kidneys
To recap, the heart pumps blood through the arteries and collects it through the veins. By pumping, among other organs, it nourishes the kidneys. Blood is collected from the kidneys through veins (a main vein: the inferior vena cava) that goes directly to the heart. Well, when the heart stops pumping properly, it cannot mobilize all that volume of blood that it needs to mobilize. Not being able to empty itself completely, blood begins to accumulate in the organs from where it is no longer being able to collect it completely. Thus, it is easy for the legs to swell or, as in this case, for the accumulation of pressure in the vein that came from the kidneys, causing them to also be damaged.
Similarly, when the kidneys are damaged, the hormonal system that controls blood pressure goes into overdrive in an attempt to increase blood flow to the kidneys, causing the heart to pump against the increased blood pressure. and ends up suffering as a result of the increased workload. This phenomenon, in which the dysfunction of one organ leads to the collapse of the other, is called “cardiorenal syndrome” .
There are a total of 5 different types of cardiorenal syndrome that produce different manifestations in the kidney or heart and can lead to subsequent complications such as heart failure, acute kidney injury, chronic kidney disease, etc. In addition, since the kidney must filter waste substances, if they are not filtered, they also accumulate. These substances are toxic to many of our tissues, and can damage other organs.
If a doctor suspects that your patient has heart problems, it is more than likely that he or she will also test his or her kidney function. A simple blood test can determine if creatinine, a waste product normally produced by the kidneys, is elevated, indicating kidney damage.
What can be done to avoid this disease?
On some occasions, given for example a genetic predisposition, it is not always possible to completely prevent these diseases. However, the vast majority of the time we are talking about the result of what are known as risk factors. That is, the bad habits in people’s lives that, in one way or another (and this is one of them), end up taking their toll . For example, smoking, a poor diet or a sedentary lifestyle are not things that will go unnoticed for the health of your heart or your kidneys.
It is important to have a healthy and nutritious diet that includes several fruits and vegetables, whole foods, healthy protein sources such as legumes or fish, fats preferably of vegetable origin, etc. It is also advisable to carry out regular check-ups, control blood sugar if you have diabetes mellitus, keep your urine and cholesterol levels under control, and your weight. Daily physical activity also plays a critical role in maintaining heart and kidney health.
It should be noted that not all people who have heart or kidney problems develop cardiorenal syndrome. It is true that it is quite common for someone who has one of the problems to develop the other, but it is not something that happens yes or yes, simply, as there are links between both organs, there is a certain tendency to have them correlated.
References:
British Heart Foundation (s.f.). The heart-kidney link. https://www.bhf.org.uk/informationsupport/heart-matters-magazine/medical/kidney-heart-link#:~:text=for%20kidney%20disease-,Relatively%20recent%20research%20has%20shown%20that%20heart%20failure%20is%20a,blood%20in%20the%20kidneys%2C%20too.
Damman, K., & Testani, J. M. (2015, Junio). The kidney in heart failure: an update. European Heart Journal, 36(23), 1437–1444. https://doi.org/10.1093/eurheartj/ehv010
Macrovector (s.f.). Human internal organs anatomy in cartoon vector style. brain and kidney, liver and lung, stomach and heart illustration Free Vector [Imagen adaptada]. Flickr. https://www.freepik.com/macrovector
NIDDK (s.f.). Heart Disease & Kidney Disease. https://www.niddk.nih.gov/health-information/kidney-disease/heart-disease
Rangaswami, J. et.al. (2019, Marzo). Cardiorenal Syndrome: Classification, Pathophysiology, Diagnosis, and Treatment Strategies: A Scientific Statement From the American Heart Association. Circulation, 139(16). https://doi.org/10.1161/cir.0000000000000664
