Top Seven Things you Need to Know About Your Kidney’s Work
Kidneys are amazing organs.
They are located on either side of your backbone and work 24/7 to ensure that the rest of your body’s organs are provided with just the right balance of salts, acid and water to function well, while cleaning out all the waste material produced from all the food and drink we take in.
The kidneys perform these functions through the use of filters, called nephrons. Each kidney, on average has 1.5 Million nephrons! Nephrons perform their filtration and balance function, draining waste matter into tiny tubes. These tubes eventually join to form a large drain-pipe called a ureter, that drains all the waste (now called urine) into the bladder for storage. Urine is released at a time of your convenience :
Further, I bet you didn’t know that your kidneys are necessary for your body to make blood and give you healthy bones!
Let’s go into this in a little more detail.
What do your kidneys do?
1. Your kidneys clear out waste
As we eat and drink, the nutrients from food is used to produce energy in our bodies, repair bone, muscle, nerves and generally keep us healthy. However, just like any factory, this process produces by-products that are waste. Examples are urea and creatinine, which we measure when we do kidney function tests (UEC). Urea and creatinine are released back into the blood stream as they are made and as this blood passes through the kidney, the nephrons are able to filter the waste.
So, if we were to check the level of urea and creatinine in the blood at any time, the levels should be low, as the kidneys never allow these waste products to accumulate.
2. Your kidneys also get rid of acid
Your body also makes acid as a waste product! And your kidneys have the amazing ability to neutralize this acid as your blood passes through it. The ensures that the pH in the body remains at a level where all other organs can function well.
3. Your kidneys do salt balance
If you have ever thought ‘surely, I don’t need all of the salt in these potato crisps!’, you were probably right. And functioning kidneys make sure that you don’t retain all the salt (sodium chloride) that you consume.
As blood passes through nephrons, kidneys are able to remove excess salt or even retain salt in the body when required. The same is done for potassium, calcium, phosphate and other salts.
Salts within our bodies must be maintained within very limited and specific levels. Any increase or decrease could result in the heart, brain, muscles or even the kidney itself working poorly and could be dangerous to one’s health. In the long term, it would have effects on the bones too!
4. Kidneys remove excess water
Your body is a factory. It uses the water that you drink for cleaning, mixing, diluting, as a solvent, thermal control… but what you drink, after being used, must come out.
So as your blood passes through your kidney, excess water is filtered out. So, you may have noticed that if you drink a lot of water, you would urinate more frequently, and vice versa.
5. Your kidney is needed to make blood
Red blood cells (RBC) are necessary to transport oxygen around the body. RBC are constantly being made in the bone marrow as they only have a lifespan of 3 months. RBC could also be destroyed earlier by infection, in certain genetic illnesses like sickle cell disease or when lost through bleeding.
As blood passes through your kidney, specialized cells are able to detect when the blood level is low. The kidney then produces EPO (Erythropoietin), a signal that travels to the bone marrow, causing it to increase the rate of production of RBC.
People with kidney disease may thus have with a low blood level (anemia). This is not because the body is incapable of making blood; rather, it is because the kidney cannot signal to the bone marrow that blood needs to be made.
6. Kidneys are needed for healthy bones
As we move, we are constantly straining our bones. Hence, the bones are being constantly repaired, which needs a constant supply of calcium and vitamin D.
This is where the kidney comes in. Vitamin D absorbed from the sun and food needs to be activated in the kidney before it can be used.
In people with kidney disease, bones may become weak and fragile because of an inability to activate vitamin D by the kidney.
7. Blood Pressure control
High blood pressure is a cause of kidney disease. However, kidney disease also causes high blood pressure.
Normally, kidneys play a role in maintaining normal blood pressures within the body. As blood passes through the kidney, specialized cells are able to sense whether the blood pressure is too low or too high. The kidney releases hormones that cause blood vessels to relax or become narrower as required, or cause increase or decrease in salt and water loss in urine, which results in appropriate increases or decreases in blood pressure.
Damaged kidneys however are unable to do this. They allow water and salt to accumulate in the body, cause inappropriate narrowing of blood vessels that results in raised blood pressure.
I hope this summary allows us to understand what happens as kidney function declines, something we could talk about in the next blog. Feel free to ask questions and to suggest topics that you think you would like to understand further.
Dr. K B Soki
MBChB, MMed Int. Med, FISN (UK)
Email : [email protected]
References:
The National Institute of Diabetes and Digestive and Kidney Diseases Health Information Center (NIDDK) niddk.nih.gov
Categorised in: Uncategorized
This post was written by figoplus