Persons with type 2 diabetes are especially prone to kidney disease. The best thing you can do to avoid problems with your kidneys is to keep your blood glucose and blood pressure levels under control and drink plenty of water. Here’s the story.
You have two kidneys. They are shaped like beans with concave and convex sides and are about the size of a fist. They are located at the bottom of the rib cage, one to the left and one to the right of your spine.
Functions of kidneys
Your kidneys are multi-functional. But their main job is to get rid of waste. They remove the waste products that arises when you digest food and drink, as well as excess organic molecules (such as glucose).
They are an essential part of your urinary system. Kidneys filter your blood and remove water soluble wastes which are sent to your bladder. While producing urine, the kidneys also excrete wastes such as urea and ammonium.
Your kidneys also regulate electrolytes, maintain the acid-base balance, and keep your levels of salt, potassium and phosphorus in check. By maintaining the salt and water balance, and producing the enzyme renin, they help regulate your blood pressure.
The kidneys also produce hormones that help make red blood cells, as well as an active form of vitamin D needed for the health of your bones.
As you can see, your kidneys are a vital part of your body’s processes and have a lot of work to do. Every day they filter enough blood to fill a large 200 litre bathtub and produce about half a gallon of urine.
Your kidneys are highly versatile and have built in redundancy.
If you are missing a kidney―some people are born with only one kidney―or if one of your kidneys is damaged or has been removed, the remaining one can grow until it is nearly as large as two kidneys together. That helps the sole kidney do the job of both.
This means that you can donate a kidney to someone else, such as a member of your family, a friend or even a stranger. Thousands of people do so every year and stay perfectly healthy afterwards. In fact, kidney transplants are the most common organ donations in the world.
Kidney stones are pieces of hard solid matter made in the kidneys from minerals in the urine. They are formed when there is too much of a particular substance (such as calcium) in your urine. They can vary in size from as tiny as a grain of sand to as big as a pearl or (rarely) a golf ball.
Kidney stones usually go down the urinary tract and pass out when you urinate. Indeed many stones are formed and passed without causing symptoms.
But if the stones grow large enough (at least 3mm) they can block the urethra. This causes pain, beginning in the lower back and radiating to the groin. Other symptoms include nausea, vomiting, fever, blood in the urine and painful urination.
One of the major causes of the formation of stones is dehydration due to a low intake of fluids. The risk of forming kidney stones is increased when you eat lots of animal protein, salt, refined sugars, fructose, and high fructose corn syrup. Drinking grapefruit and apple juice also increases the risk.
Developing kidney stones can run in the family. The best way to prevent stones from developing is to drink enough fluids that you produce more than two litres of urine every day, and adhere to a low-sugar, low-salt diet that contains minimal animal protein. You should also avoid drinking colas.
How kidneys are damaged
There are two broad types of damage to your kidneys:
- acute kidney injury, and
- chronic kidney disease
Acute kidney injury
Acute kidney injury, also known as acute renal failure (ARF), is a sudden loss of kidney function. There are many ways in which this can happen. ARF can occur following:
- a sudden reduction in the flow of blood to the kidneys due to a traumatic injury with severe loss of blood
- damage to the kidneys due to shock from a severe infection
- damage from toxins or certain drugs
- obstruction of the flow of urine
- complications during pregnancy
Runners who don’t drink enough fluids when competing in long-distance endurance events can suffer a sudden breakdown of muscle tissue. The breakdown releases myoglobin, a protein found in muscle tissue which only appears in the bloodstream after muscles are injured; this protein can damage the kidneys severely and result in ARF.
Chronic kidney disease
Kidney damage that lasts longer than three months is known as chronic kidney disease (CKD). It is particularly dangerous because you may not have any symptoms until considerable (often irreparable) damage has been done.
The two most common causes of CKD are:
- diabetes (both types 1 and 2), and
- high blood pressure
Other causes of CKD include chronic viral illnesses (such as HIV/AIDS and hepatitis B and C), urinary tract infections within the kidneys themselves, inflammation following a strep infection, congenital defects, toxins, some medical drugs, and the use of recreational drugs that are injected.
You can also damage your kidneys by eating too much animal protein and not drinking enough water.
Your kidneys are made up of millions of extremely small filtration units which purify your blood and send the waste products out into the urine. These tiny filtration units can be damaged by high glucose levels (diabetes) and high blood pressure (hypertension).
Unused glucose in your bloodstream is filtered by your kidneys and then normally reabsorbed back into the bloodstream. However there is a limit to the rate at which the kidneys can filter and return glucose.
When this limit is exceeded―as it can be if you don’t get your diabetes under control―your kidneys become stressed from over-work and the glucose starts to spill into the urine.
Your kidneys are particularly sensitive to high blood pressure. At the same time, they play an important role in the regulation of blood pressure and if they have been damaged, they can lose some of their ability to keep blood pressure down.
The problem is circular―high blood pressure damages the kidneys and damage to the kidneys can contribute to high blood pressure.
Beating kidney disease
In the early stages of the disease there are usually no symptoms. But as things get worse, changes in bathroom habits―having to go more or less often―can signal a problem.
You may also feel tired, have muscle cramps, lose your appetite, and have swollen hands or feet and dry, itchy skin.
The only fix is to regulate your blood pressure, using medication prescribed by your doctor, and beat the effects of diabetes by following a low-sugar, low-fat, low-salt and high-fibre diet and avoiding eggs and dairy products.
Getting both your blood pressure and blood glucose levels under control is imperative because once your kidneys stop working your body begins filling up with wastes, fluids, and toxins.
With your kidneys out of action, the only way to get rid of these is to go on dialysis―using a machine that acts as an artificial kidney, cleaning your blood―a very inconvenient, extremely messy and highly uncomfortable procedure.
If you allow damage to your kidneys to develop, you will end up needing kidney dialysis at least three times a week. In the end, you will probably need a kidney transplant.
Above all else, drink plenty of water. Check when you go to the toilet: is your urine clear to light yellow in colour? It should be―if you are drinking enough liquids.