Friday, January 9, 2015

How our kidneys work

The role of the kidneys is often underrated when we think about our health. In fact, the kidneys play an important role in the daily workings of our body. They are so important to health that nature gave us two kidneys to cover the possibility that one might be lost to an injury. They are so important that with no kidney function death occurs within a few days.

We can live quite well with only one kidney and some people live a healthy life even though born with one missing. But while bones can break, muscles can waste away and the brain can sleep without risk to life, if both of your kidneys fail, as happens in end stage kidney failure, the body dies without life saving dialysis.

How do our kidneys work? 
The kidneys play a major role in maintaining your general health and wellbeing. Think of them as an extremely sophisticated, environmentally friendly, waste disposal system which sorts non‐recyclable waste from recyclable waste, 24 hours a day, seven days a week, while also cleaning your blood.

Most people are born with two kidneys, each one about the size of an adult fist, are bean-shaped and weigh around 150 grams each. The kidneys are located at both sides of your backbone just under the rib cage or above the small of your back. They are protected from injury by a large padding of fat, your lower ribs and several muscles.

In each kidney, blood is filtered through millions of mini‐filters called ‘nephrons’. The excess fluid and unwanted chemicals from this filtering process become urine and are passed from the kidneys to your bladder.

What do your kidneys do?
Our kidneys are small biological marvels with a fascinating design. Every hour your blood supply circulates through the kidneys about 12 times. Each day your kidneys process around 200 litres of blood, with around 1 to 2 litres of waste leaving the body as urine.
The kidneys also play a role in the production and regulation of several important hormones and enzymes, which help to:

  • Control blood pressure
  • Make red blood cells
  • Maintain strong and healthy bones
All this makes the kidneys a vital player in your body’s mechanism and your overall health.
Anatomy of the kidneys
We have about a million hairpin-like glomeruli at birth, but lose about 100,000 of these every decade of life. Droplets of filtered blood pass through a number of tubules (tiny tubes) into the medulla, a central collecting region. The glomeruli and tubules together make up nephrons, long and extremely fine tubes which, if connected, would run for 80 kilometres (50 miles).
Cleaned blood returns to the body by the renal vein. Waste and extra water removed by the kidney passes through a tube called the ureter to the bladder, where it is stored as urine or wee. When the bladder is full, urine passes out of the body through another tube called the urethra.
The process of removing waste and extra water in simple terms is:
  • food and drink enters the stomach and are broken down into nutrients
  • solid waste products are removed and nutrients enter the bloodstream.
  • nutrients are used by the body for energy, growth, repair and maintenance of body functions.
  • this process creates waste which is removed by the kidneys.
  • extra nutrients not immediately needed by the body are also removed by the kidneys.
  • waste products and extra water move from the kidneys to the bladder, then leave the body as urine
Our kidneys are designed to last a life-time, they do an amazing job!  It is important to care for them.
We recommend these kidney education tools below for a visual introduction to the kidney. Click on diagrams to view animations * How our kidneys work * How dialysis works to replace the work of healthy kidneys,

How Kidneys Work How Dialysis Works
Click diagram go to animation
How a healthy kidney works> 
Click diagram go to animation
Structure of the kidneys and bladder>
Kidney Health Australia acknowledges DaVita for allowing use of these images their excellent teaching resource on our website.
How can I look after my kidneys?
There are many risk factors that can contribute to kidney disease, and it’s important to be aware of these risks and take the right steps to prevent kidney damage.
Stop Smoking
If you don’t smoke, don’t start. If you do, quit! This is the simplest, most important lifestyle habit to change to reduce the risk of kidney disease. People who smoke are three times more likely to have reduced kidney function, and have a four to five times greater risk of heart attack and stroke. Tips to help you quit:

  • Get the appropriate help. Order a free QUIT pack - call QUIT Hotline 137 848 or contact your local community services directory or health centre for a referral to a smoking cessation program.
  • Surround yourself with people who are non‐smokers.
  • Talk to your general practitioner. Research shows that spending as little time as three to five minutes talking with your health practitioner can increase your quit rate.
  • Find healthy alternatives to smoking, such as meditation and yoga.
What can I do to keep my kidneys healthy?
Key recommendations to staying healthy and maintaining kidneys health are:

  • Keep your blood pressure below 130/90 and maintain healthy levels of cholesterol
  • If you have diabetes make sure you actively treat your blood glucose levels - normal levels are 4-6 mmol/L before meals and 4-8 mmol/L two-hours after meals.
  • It’s important to have your cholesterol levels checked regularly - recommended level is no higher than 5.5 mmol/litres.
  • Lead a healthy lifestyle and maintain healthy weight, be active for more than 30 minutes most days.
  • Eat a balanced healthy diet low in saturated fats.
Healthy Eating
The food you eat plays a huge role in the health and well being of your body. As well as providing the body with a variety of nutrients, food choices can also help in weight reduction and weight control. Tips to help you do this are:

  • eat healthy foods - with as many fresh ingredients as possible.
  • don't over eat - always leave a meal feeling like you could eat a little bit more.
  • eat breakfast - a good breakfast activates your metabolism first thing in the morning.
  • avoid fad diets - they are hard to maintain over a long period and can create or worsen ill health.
  • check nutrition panels on all parceled foods you buy - choose only foods that list a low percentage of sugar and salt and are low in saturated fats - find out about food ingredients.
To satisfy thirst - drink water instead!
Drink plenty of fluids and listen to your thirst. Water is the recommended choice, it is also calorie-free, inexpensive and readily available. Sugar drinks have lots of calories, while caffeine and alcohol are both diuretics and can leave the body dehydrated.

Research also states that one drink containing sugar each day, has been shown in females to be associated with an 80 % increase in the risk of acquiring diabetes. Choose to drink water instead!
Note: Bottled mineral water contains salt which can lead to fluid retention and even increased blood pressure in susceptible people. Check the label and choose low sodium varieties (less than 30mg sodium per 100ml).

Losing weight can reduce how hard your kidneys need to work
Weight loss can also lead to a decrease in the amount of protein lost via urine. High levels of protein in the urine can make your kidney function worse. Obesity may also cause some people with existing forms of some kidney disease to lose their kidney function more rapidly.

There is also evidence to suggest excess weight is also associated with an increased risk of kidney cancer. If you are overweight, you have an increased risk of developing diabetes and high blood pressure - both are major risk factors for kidney disease. Losing as little as 5 kilograms reduces blood pressure in most people who are 10% above a healthy weight.

Do at least 30 minutes of physical activity most days of the week
Stay fit. The key is to start slowly and gradually increase time and intensity of activities. Physical activity leads to increased strength, stamina and energy. You can break down any activity into 3 x 10 minute bursts, which can be increased as fitness improves.

STOP exercising without delay, tell your health care team, or go to hospital if you:
-  have chest pain or pressure
-  feel dizzy or light headed
-  have an irregular or fast heart beat that persists when the activity is completed
-  have excessive shortness of breath
Limit alcohol intake
Excessive alcohol intake can lead to heart disease and high blood pressure, increasing the risk of kidney disease. Tips to cut down on your alcohol intake:
  • Limit alcohol to less than two standard drinks per day.
  • Ask for ice with your drinks – when the ice melts it will dilute alcohol.
  • Alternate your drinks by having a glass of water in between each alcoholic drink.
  • If you want to feel like you’re partaking in a drinking session, fake it – drink your water from a wine glass.
Enjoy Life
Good health and wellbeing means that we are healthy from all dimensions of our lives – physically, mentally, socially and spiritually. Tips for an enjoyable life:
  • Have less stress in your life.
  • Do the things you love.
  • Spend more time with people you enjoy being
  • with – those who challenge you to be more… not less.
  • Balance the load.

 KidneyEd TV
Our collection of YouTube videos, grouped into playlists, enable you to learn more about the kidneys, urinary system and related topics. View reviewed kidney health education videos at KidneyHealthAus - on YouTube.
Without any kidney function our body dies. Some kidney function is essential for life!

The KidneyWHAT CAN GO WRONG WITH THE KIDNEYS? Most kidney diseases attack the nephrons. Sometimes kidney failure can happen quickly, caused for example by a sudden loss of large amounts of blood or an accident. A sudden drop in kidney function is called Acute Kidney Failure and is often short lived, but can occasionally lead to lasting kidney damage.

More often kidney function worsens over a number of years. This is actually good news, because if kidney disease is found early, medication, dietary and lifestyle changes can increase the life of your kidneys and keep you feeling your best for as long as possible.
Kidney disease progression can also be slowed with medicines which help to protect your kidneys. Your GP can prescribe these medicines for you. Talk to your local pharmacist when you have your prescription filled. Take the test at Check My Kidneys to find out if you are at increased risk of kidney disease.
What does Chronic Kidney Disease mean?
If you lose over one third of your kidney function for over 3 months, it is called Chronic Kidney Disease or CKD.

Sometimes kidney disease leads to kidney failure, which requires dialysis or a kidney transplant to keep you alive. Early detection and treatment can help prevent kidney failure and the need for dialysis or transplant treatment.
If you are diagnosed with CKD, this means that your kidneys have been damaged and are not working as well as they should normally. Kidney disease is called a ‘silent disease’ as there are often no warnings.
  • It is not uncommon for people to lose up to 90% of their kidney function before getting any symptoms.
  • People can live a near normal life with as little as 20 percent of their total kidney function.
  • When symptoms do occur the initial signs may be general, such as feeling tired or generalised itching. 
  • As kidney disease progresses, symptoms can include changes in the urine (reduced volume, discolouration, blood or pus), nausea and vomiting and appetite loss.
  • Other symptoms include swollen or numb hands and feet (because of water retention), weakness and lethargy, darkened skin and muscle cramps. 
  • About 50 people a day die of a kidney related disease.

How do you know if you have CKD? 
In most cases CKD does not cause any symptoms and is detected because a test has shown an abnormality. It may be a urine test for blood or protein; an X-ray or scan of the kidneys; or a blood test to measure kidney function. Most cases are discovered by your GP as part of normal care.
How common is CKD?
1 in 9 Australians over age 25 years have at least one clinical sign of existing CKD, such as reduced kidney function or evidence of kidney damage. It is less common in young adults.

In the older person it is more common due to the natural aging of the kidneys. A number of diseases can damage the kidneys such as diabetes, hypertension (high blood pressure) and some inherited conditions.