Is there a link between high blood pressure and kidney disease?
Hello all,
Did you know that high blood pressure or hypertension is the second leading cause of kidney disease? The leading cause is diabetes, but high blood pressure is a close second. The treatment of hypertension is one of my passions, so I want to make sure you know as much as you can about this important topic. Because of this, I am going to spend a bit more time on this topic. This will be a three part series. In the first article we will talk about what high blood pressure is, how it can cause kidney damage, and what some of the symptoms might be. In Part 2, we will cover risk factors, and in Part 3 we will discuss treatment strategies.
What is blood pressure?
Let’s start with the basics. Blood pressure is the force of the blood pumping against the blood vessel walls as the heart pumps blood out through the body. High blood pressure is when the pressure on the blood vessel walls increases. This can be due to an increased blood volume because of an excess of fluid in the blood, or the pressure can be increased because the blood vessels are narrowed or stiff.
It might help to think of this in the following way. Think of your blood vessel as a piece of flexible tubing that allows fluid (your blood) to flow through it. But now imagine that you have the same tubing but you try and push through much more fluid – obviously the pressure in the tubing will increase to accommodate the increased fluid. Or if the tubing had become rigid or narrowed this would cause an increase in pressure.
Your blood pressure measure is represented by two numbers, for example 120/80. One number is your systolic pressure – this is the measure of pressure when the heart pumps out. The second number is your diastolic pressure and this is the measure of the pressure between heart beats.
Left untreated, high blood pressure can cause damage to blood vessels. Damage to smaller blood vessels can be even more serious and because there are small vessels in the kidneys, this can impact kidney function.
If the blood vessels in the kidney are damaged they will not be able to filter the blood properly and this can lead to kidney disease.
Healthy kidneys also play an important role in regulating blood pressure by producing a hormone called aldosterone. When the kidneys are damaged, this function can be impaired causing blood pressure to rise even more.
Normal blood pressure is considered to be a systolic pressure of below 120 and a diastolic pressure of less than 80. You should speak with your doctor about your blood pressure goals.
Here is a link from the American Heart Association to the various blood pressure levels: http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/KnowYourNumbers/Understanding-Blood-Pressure-Readings_UCM_301764_Article.jsp#.WmtXPojwbIU
Blood pressure is a complex condition and this is only a short overview so be sure to check out some of the websites listed in the reference section.
So now that you have some background on what high blood pressure is, and how it can impact your kidneys, let’s talk more about some signs and symptoms.
Often symptoms of high blood pressure can go unnoticed for a long period of time because they are subtle. Some of the most common signs are swelling of their legs, ankles, feet, hands and face. This swelling is called edema and is caused because the kidneys are not able to get rid of extra fluid and salt. As kidney disease progresses, other symptoms may develop.
Yours in good health
The Doc Brown
References:
DaVita Kidney Care https://www.davita.com/kidney-disease/causes/hypertension
National Institutes of Health; National Institute of Diabetes and Digestive and Kidney Diseases https://www.niddk.nih.gov/health-information/kidney-disease/chronic-kidney-disease-ckd/high-blood-pressure
American Heart Association http://www.heart.org/HEARTORG/Conditions/HighBloodPressure/LearnHowHBPHarmsYourHealth/How-High-Blood-Pressure-Can-Lead-to-Kidney-Damage-or-Failure_UCM_301825_Article.jsp#.Wmtb2IjwbIW