This month and next month’s articles are about the kidneys, and what chronic kidney disease actually means. I know I have mentioned chronic kidney disease (CKD) in previous columns, especially as a complication of high blood pressure, diabetes, and gout. Our kidneys are often a body part that we don’t tend to think about very much, although they are important. According to Kidney Care UK, there are around 3 million people in the UK living with chronic kidney disease, and it is known to contribute to over 40,000 premature deaths each year in the UK.
Most people will have two kidneys in their bodies, unless they are born with only one, or have one removed. The kidneys are each approximately the size of a fist and lie below the rib cage at the back of your body. The job of the kidneys is to filter the blood as it runs through them. This is a complicated system which results in the removal of extra fluid from the blood, and any ‘waste’ that is in the blood; the result of this is urine. The kidneys produce urine which then flows down from the kidney to the bladder in little tubes called ureters. The urine is stored in the bladder until you go to the toilet, where it passes through another small tube called your ureter and leaves your body. This is called the urinary tract.
The process of creating urine is complicated. This is because the kidneys work in different ways to ensure we have the right balance of water, salts, and minerals to allow our bodies to work properly. If we take extra substances into our bodies, like some medications or drugs, the kidneys will filter these out into the urine to get rid of them. You can tell your body is keeping a balance if everything is working well – the more you drink, the more you pee! The kidneys also produce hormones which have special roles in controlling blood pressure, making blood cells, and maintaining healthy bones.
So that is what the kidneys are supposed to do if everything is working well. I hope you can see that they are important to keeping our bodies in balance. If the kidneys stop working so well, then it is important for this to be picked up. How well the kidneys are working can be assessed by blood and urine tests. Often changes in kidney function will have no symptoms, which can make it difficult to detect. Blood tests tell us how well the kidneys are working on a scale of 1 to 5. Grade 5 is the most serious reduction in kidney function and at this point dialysis or a kidney transplant may be considered – but more on this next month when we will cover CKD in more detail.
Chronic kidney disease is a big problem in the UK, but so is Acute Kidney Injury (AKI) which is a sudden drop in kidney function. AKI can happen with acute illness and is often seen in patients admitted to hospital. It is serious, with 100,000 deaths associated to it each year.1 AKI can happen with starting new medications that have an effect on the kidney, with infections, or with dehydration. This is why we like to check blood tests for the kidneys if we start some medications, or if you are unwell with vomiting or diarrhoea that may cause dehydration, you may be advised to stop certain medicines too.
Next month we will move on to more about chronic kidney disease, its causes, symptoms and how it is managed. Until then, keep drinking plenty of water, especially in warm weather, to keep well hydrated and your kidneys happy!
You can find more information on the health of your kidneys on the NHS website nhs.uk/live-well/healthy-body/keeping-your-kidneys-healthy