Kidneys- All You Need To Know About The Kidneys

What are the Kidneys and Why are they important?

The kidneys are two bean-shaped organs, each about the size of a fist. They are located just below the rib cage, one on each side of the spine. Every day, the two kidneys filter about 120 to 150 quarts of blood to produce about 1 to 2 quarts of urine, composed of wastes and extra fluid. The urine flows from the kidneys to the bladder through two thin tubes of muscle called ureters, one on each side of the bladder. The bladder stores urine. The muscles of the bladder wall remain relaxed while the bladder fills with urine. As the bladder fills to capacity, signals sent to the brain tell a person to find a toilet soon. When the bladder empties, urine flows out of the body through a tube called the urethra, located at the bottom of the bladder. In men the urethra is long, while in women it is short.

Each kidney is made up of about a million filtering units called nephrons. Each nephron filters a small amount of blood. The nephron includes a filter, called the glomerulus, and a tubule. The nephrons work through a two-step process. The glomerulus lets fluid and waste products pass through it; however, it prevents blood cells and large molecules, mostly proteins, from passing. The filtered fluid then passes through the tubule, which sends needed minerals back to the bloodstream and removes wastes. The final product becomes urine.

Kidneys are essential to our health as they get rid of excess water and toxins, regulate blood pressure, make red blood cells and keep the bones strong. Kidneys are important because they keep the composition, or makeup, of the blood stable, which lets the body function. They prevent the build-up of wastes and extra fluids in the body; they keep levels of electrolytes stable, such as sodium, potassium and phosphate. They also produce hormones that help to regulate blood pressure, make red blood cells and keep bones strong.

Kidney Statistics

• Kidneys filter around 180 litres of blood per day.

• Around 64,000 people in the UK are being treated for kidney failure.

• Around 5,200 people are waiting for a kidney, around 3,300 transplants are carried out each year in the UK.

• An estimated of around 60,000 people in the UK die prematurely due to kidney disease each year.

• Acute Kidney Injury (sudden drop in kidney function due to serious illness) affects 1 in 5 people in the UK who are admitted to hospital as an emergency.

• Nearly 1,000 children in the UK have failed kidneys which require lifelong treatment.

• 1 in 4 adults and 1 in 5 children in the UK are severely overweight, which is a major risk of developing kidney disease.

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What is Chronic Kidney Disease and What are the Stages of CKD?

Chronic kidney disease is a long term condition where the kidneys don’t work as well as they should; it is characterised by a gradual loss of kidney function over time. There are five stages of chronic kidney disease. Your doctor determines your stage of kidney disease based on the presence of kidney damage and your estimated Glomerular Filtration Rate (GFR), which is a measure of your level of kidney function. 

Stage 1 CKD

A patient at stage 1 CKD has a GFR of 90 or higher. Kidney function is normal with a few or no physical symptoms. At this stage because the kidneys are still well most people will not know they are at stage 1 of CKD. If a person is diagnosed with stage 1 of CKD it is usually because they are being treated for diabetes, high blood pressure or they have a family history of kidney disease. The signs of stage 1 CKD include higher than normal levels of creatinine or urea in the blood, blood or protein in the urine, evidence of kidney damage through an MRI, CT scan, ultrasound or x-ray, a family history of kidney disease.

Stage 2 CKD

A patient at stage 2 CKD has a GFR of 60-89. There are usually few or no physical symptoms at this stage. Although the kidneys are not working 100% at this stage the kidneys are still well so most people will not know that they are at stage 2 of CKD. If a person is diagnosed with stage 2 CKD it is normally because they are being treated for diabetes, high blood pressure or they have a family history of kidney disease. The signs of stage 2 CKD are the same as stage 1.

Stage 3 CKD

A patient at stage 3 CKD has moderate kidney damage. At Stage 3a GFR is 45-59 and Stage 3b is 30-44. As the function of the kidney will be declining waste products will start to build up in the blood. The toxic build-up of high concentrations of nitrogenous substances is called uraemia. The signs of stage 3 CKD include fatigue, oedema (fluid retention), muscle cramps or restless legs, urine changes, colour change due to the presence of blood, loss of appetite, skin changes such as itching sensation, dry and flaking skin, diarrhoea or constipation, back pain.

Stage 4 CKD

A patient at stage 4 CKD has severe kidney damage. At stage 4 GFR is 15-30. As the function of the kidney will be declining waste products will start to build-up in the blood. The toxic build-up of high concentrations of nitrogenous substances is called uraemia. It is likely that a patient with stage 4 CKD will need dialysis or a kidney transplant soon. The signs of stage 4 CKD include fatigue, sleep problems, restless legs, muscle cramps, fluid retention, kidney pain felt in the back, urine changes, loss of appetite, diarrhoea, constipation, nausea, vomiting, changes in taste, metallic taste in the mouth, difficulty in concentrating, skin changes, nerve problems.

Stage 5 CKD

A patient with stage 5 chronic kidney disease has end stage renal disease with a Glomerular Filtration Rate (GFR) of 15ml/min or less. At this advanced stage of kidney disease, the kidneys have lost nearly all their ability to do their job effectively, and eventually dialysis and kidney transplant is needed to live. The signs of stage 5 CKD include loss of appetite, nausea, vomiting, headaches, being tired, being unable to concentrate, itching, making little or no urine, swelling especially around the eyes and ankles, muscle cramps, tingling in hands or feet, changes in skin colour, increased skin pigmentation.

What are the Risk Factors of Chronic Kidney Disease?

• High Blood Pressure

• Diabetes

• Obesity

• High Cholesterol

• Kidney Infections

• Blockages in the flow of urine

• Glomerulonephritis- a group of diseases that cause inflammation and damage to the kidneys filtering units. These disorders are the third most common type of kidney disease

• Inherited diseases such as polycystic kidney disease, which causes large cysts to form in the kidneys and damage the surrounding tissue

• Malformations that occur as a baby develops into the mother’s womb. For example, a narrowing may occur that prevents normal outflow of urine and causes urine to flow back up to the kidney. This causes infections and may damage the kidneys

• Lupus and other diseases that affect the body’s immune system

• Obstructions caused by problems such as kidney stones, tumours or an enlarged prostate gland in men

• Repeated urinary infections

What are the Symptoms of Chronic Kidney Disease?

• Tiredness

• Swollen ankles, feet or hands

• Shortness of breath

• Feeling sick

• Blood in your urine

• Trouble concentrating

• Poor appetite

• Sleeping problems

• Muscle cramps

• Skin problems

• Need to urinate more often

You must see your GP if you experience persistent or worrying symptoms that you believe could be due to kidney disease.

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How to keep your Kidney’s healthy

• Monitor your blood pressure- High blood pressure accelerates kidney damage. To protect yourself from kidney disease you should also maintain a diet low in salt and saturated fats.

• Keep fit and active- This helps to reduce your blood pressure and therefore reduces your risk of kidney disease.

• Don’t smoke- Smoking slows blood flow to the kidneys, decreasing their ability to function properly.

• Eat healthily and keep your weight in check- This helps prevent diabetes, heart disease and other conditions associated with kidney disease.

• Get your kidney function tested- If anyone in your family has suffered from kidney disease, if you are diabetic or if you have high blood pressure or if you are overweight or obese.

• Keep well hydrated- This helps the kidneys clear sodium, urea and toxins from the body which can significantly lower the risk of developing kidney disease.

• Get advice- If you know that you have kidney disease and become unwell for example, excessive diarrhoea or excessive vomiting, then get advice from a medical professional immediately.

• Cut down on alcohol- Drinking excessive amounts of alcohol can cause your blood pressure and cholesterol levels to rise to unhealthy levels. Stick to the recommended limit which is not to drink regularly more than 14 units of alcohol per week.

• Urine test- You could help save your kidneys with a simple urine test, this estimates the amount of protein, albumin that is in your urine. You would need to go to see your GP to ask for this test and they will discuss further steps to take.

• GFR blood test- tells you how well your kidneys are working to remove wastes from your blood. It is the best way to check kidney function. Over 90 is good, 60-89 should be monitored, less than 60 for 3 months indicates kidney disease. You would need to go to see your GP to ask for this test and they discuss further steps to take.

• Watch out for your risk factors and monitor them to make sure they are being controlled well.

• Drink plenty of water and avoid sugary drinks such as fizzy

• Do activities that help you to relax and reduce stress.

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