Kidneys – how important are they? They are very important! As a matter of fact, they are the fundamental organs of human body. Take them out and no human can survive. They are extremely complex in mechanism and they have two primary functions – (a) blood purification and (b) waste elimination. So, let us not waste any more time and take a look at 35 interesting facts about human kidneys.

Facts About Human Kidneys: 1-5

1. The blood flow in kidneys is higher than the blood flow in heart, liver, and brain.

2. Kidneys measure around 4.5 inches in length.

3. Kidneys are no bigger than a standard computer mouse or a cell phone.

4. Each individual kidney weighs around 4-6 ounces.

5. In case of new born human babies, the kidney to body weight ratio is 3 times the kidney to body weight ratio in adults.

Facts About Human Kidneys: 6-10

6. In case of adults, kidneys form only 0.5% of the entire body weight.

7. Exactly half of one single kidney is capable of doing the job that is performed by two kidneys together.

8. Each individual kidney consists of at least 1 million and up to 2 million nephrons. Nephrons are nothing but very tiny filters that are capable of filtering blood and eliminating the waste materials.

9. In a single hour, kidneys receive around 120 pints of blood.

10. Though the kidneys weigh on 0.5% of the entire body weight, they actually receive more arterial blood compared to other organs in body. Almost 25% of the blood pumped by the heart goes to the kidneys.

Facts About Human Kidneys: 11-15

11. Once a person reaches the age of 40, the number of functional nephrons present in each kidney start falling at a rate of 1% a year.

12. Despite the decline in the number of functional nephrons in kidneys after the age of 40, the kidneys continue to function normally because the nephrons have a tendency of enlarging once the demise begins.

13. If the nephrons in both kidneys are taken out and placed end to end horizontally, they will cover a distance of 16 kilometers.

14. If one kidney is taken away and the functional capacity of the other kidney is reduced to just 75%, it can still sustain life. This happens because the nephrons are capable of enlarging and handling excess load. This is known as hypertrophy.

15. Kidneys are responsible for maintaining a constant amount of fluid in the body. The entire blood in the body gets filtered around 400 times in a day through the kidneys.

Facts About Human Kidneys: 16-20

16. When dehydration sets in, kidneys stop producing enough urine until hydration is restored and blood volume increases.

17. If the blood pressure in kidneys fall, they start sending out signals to the rest of the body. As a result of these signals, the blood vessels throughout the body become smaller to increase the pressure. This ensures that blood reaches every part of the body.

18. If the oxygen content of the blood falls, the kidneys can sense that as well. Once the kidneys sense a lack of oxygen, they create a hormone which triggers increased production of red blood cells. RBCs are responsible for carrying oxygen. As RBC count increases, the oxygen content of the blood also increases.

19. Kidneys pump around 400 gallons of recycled blood every day.

20. Kidneys filter and return around 200 quarts of fluid into the bloodstream each day. Nearly 2 quarts are lost in form of urine while the remaining 198 quarts are recovered.

Facts About Human Kidneys: 21-25

21. Kidneys are connected to bladder with the help of two tubes known as ureters. It is the bladder where the urine is stored. The urine that we excrete is stored anywhere between 1 and 8 hours. Interesting fact is that we don’t urinate until the bladder is half full. Once the half of the bladder is full, signals are sent to the brain which in turn tells us that it is time to urinate.

22. Yet another interesting fact about kidneys is that they are capable of activating vitamin D in our body. This vitamin is usually produced by special skin cells when they are exposed to sunlight. If the skin fails, the job passes on to the liver. If the liver fails, the job finally goes to the kidneys.

23. Some children are born with only one kidney. For them, the single kidney eventually grows to the extent where its weight is equal to the combined weight of two kidneys.

24. Excessive antacids and milk can cause kidney stones.

25. Pancreas are stimulated by sugar to produce insulin that keeps sugar levels at check. If the sugar level in body increases, excess insulin is produced. This forces the body to excrete extra calcium through urine, which is yet another cause of kidney stones.

Facts About Human Kidneys: 26-30

26. Throughout the day, the kidneys filter and produce around 1000 to 2000 milliliters of urine. So in general we excrete around 1.5 liter urine on an average in a single day.

27. Malfunctioning kidneys can lead to the development of anemia. Studies reveal that most anemic patients usually suffer from some kind of kidney disease.

28. Kidney disease can never be reversed. Its progression can only be slowed down.

29. High BP and diabetes can both lead to failure of kidneys.

30. When the kidney functions are completely lost, it is known as ESRD or End Stage Renal Disease.

Facts About Human Kidneys: 31-35

31. People suffering with ESRD can live longer with help of kidney transplant or dialysis.

32. The first ever kidney transplant was conducted by Yuri Voronoy, a Russian surgeon in 1933. The transplant failed.

33. The first ever successful kidney transplant was conducted by Dr. Joseph E. Murray in December 1954. The transplant was between two identical twins. The operation took place in Massachusetts at Peter Bent Brigham Hospital.

34. Nearly 500 million people globally (which nearly 10% of global adult population) suffer from some kind of kidney problem/damage. This leads or millions of premature death every year because of Chronic Kidney disease induced cardiovascular diseases.

35. Nearly 1.5 million globally go through kidney transplant or kidney dialysis.

So, that concludes out 35 interesting facts about human kidneys. If you know other facts about kidneys and want to share them, you are most welcome. Just don’t get to scientific and keep things intelligible for everyone. Cheers!


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