What do the kidneys do?

You have two kidneys that are bean-shaped organs about the size of your fist. They are located at either side of your spine near the middle of your back.

Most people think the kidneys are only responsible for producing urine, but they have many important functions in your body:

  • They remove waste products from the body
  • They balance the body’s fluids and electrolytes
  • They release hormones that regulate blood pressure and control calcium metabolism
  • They stimulate and control the production of red blood cells
  • They produce an active form of Vitamin D that promotes healthy bones
  • They provide critical regulation of the body’s salt, potassium and acid content

When functioning normally, the kidneys accumulate urine and dispose of it through the urinary tract. Excess water and toxins from metabolic processes, along with the urine, are removed from the body as if through a filter. In addition, the acid-base balance is regulated by the kidneys to prevent excess acidity in the blood.

The kidneys have an important role in regulating blood pressure by producing hormones. Hormones from the kidneys such as erythropoietin control the production of blood cells in the bone marrow.

Kidneys also influence the amount of calcium in the blood and the production of vitamin D needed in mineralization that provides the stability of bones.

Did you know?

  • Your kidneys remove excess body water and waste 24/7
  • Healthy kidneys clean the blood about 300 times a day
  • That means about 1,500 liters of blood pass through the kidneys each day

I go to the Bathroom Often; Does that Mean my Kidneys are Failing?

Not necessarily. It could be a bladder rather than a kidney problem. When the kidneys make urine, it flows down a tube called the ureter and empties into your bladder. When the bladder becomes full, you may feel the urge to pass urine.

Some people with severe kidney disease make urine that has a lot of water, but does not contain much waste products. This means the blood has a high level of waste products, including potassium.

What is kidney disease?

Chronic kidney disease is a long, usually slow process where your kidneys gradually lose function. In the beginning you may not notice any symptoms. Blood tests such as the BUN, creatinine and glomerular filtration rate or GFR are the most accurate ways to determine if you have chronic kidney disease and at which stage.

There are five stages of chronic kidney disease, with stage 1 normal kidney function.

The disease can take years to go from below normal kidney function (chronic kidney disease stage 1) to end stage kidney failure at stage 5 where you need dialysis or kidney transplant.

The chronic form is permanent kidney damage caused by diabetes, high blood pressure (hypertension), various kidney tissue infections (glomerulonephritis) and excessive use of some medications that may reduce long-term kidney function.

Since it may be possible to slow down the progression of the disease in early stages, it is vital to get an early diagnosis and to work closely with your doctor to find the right treatment.

What are the symptoms of kidney disease?

The warning signs of kidney disease are not always obvious, especially in the early stages. Here are some possible symptoms:

  • Less urine
  • Swelling in the hands, face and legs
  • Shortness of breath
  • Appetite loss, nausea and vomiting
  • High Blood Pressure
  • Feeling cold and tired

What causes kidney disease?

Diabetes and high blood pressure are the two most common causes of kidney disease. Other causes include inherited kidney disease such as polycystic kidney disease and lupus.

High blood pressure, also known as hypertension, causes damage to the blood vessels in your organs including your brain, heart and kidneys slowly over a long period of time. In turn, if you already have kidney disease it can cause or worsen high blood pressure so it becomes a dangerous cycle.

It is important to control blood pressure and get it to normal levels in order to decrease damage to the kidneys and other organs.

How will I know if I have kidney disease?

Several blood and urine screening tests can check for kidney damage and evaluate how well your kidneys are working. Nephrologists use several sophisticated tests.

Your urine can reveal a great deal about the functioning of your kidneys. Blood in the urine, called hematuria, can indicate kidney stones, a kidney injury or a urinary tract infection. Sometimes the urine is high in protein, called proteinuria or albuminuria. Larger amounts of protein in the urine can be a sign of early kidney disease. If not controlled, increased amount s of protein in the urine can lead to kidney damage.

Blood tests can reveal the amount of waste products such as urea, creatinine and nitrogen in the blood that indicate kidney disease and its stage.

The creatinine level indicates how well the tiny filters in the kidneys are doing their job filtering out wastes. This level is called the GFR, and the higher the number the better your kidneys are functioning.

Most people do not have symptoms of decreased kidney function until the GFR is 20–30, and they do not feel sick until it is 10–15.

Like knowing your blood pressure numbers, you should know your GFR.

What is anemia?

When you have too few red blood cells in your bloodstream, less oxygen is being delivered to your heart, muscles, brain and other organs in your body. This makes you anemic with less energy and more fatigue. Anemia is commonly associated with reduced kidney function.

What is uremia?

Uremia (uremic syndrome) is a serious complication of both acute kidney injury and chronic kidney disease. It occurs when urea and other waste products buildup in the body because the kidneys are not able to eliminate them. These substances can become poisonous (toxic) to the body if they reach high levels.

Prolonged or severe fluid buildup may make the uremic syndrome worse and can cause:

  • Nausea, vomiting and weight loss
  • Changes in mental status, such as confusion, reduced awareness, agitation, psychosis, seizures and coma
  • Abnormal bleeding, such as bleeding spontaneously or profusely from a very minor injury
  • Heart problems, such as an irregular heartbeat, inflammation in the sac that surrounds the heart (pericarditis), and increased pressure on the heart
  • Shortness of breath from fluid buildup
  • Kidney dialysis is usually needed to relieve the symptoms of uremic syndrome until normal kidney function can be restored.

How is kidney disease treated?

You may reduce some of the progression of chronic kidney disease with lifestyle changes such as:

  • Controlling high blood pressure and blood sugar
  • Eating a healthy lower protein and lower salt diet
  • Losing weight
  • Stopping smoking
  • Exercising
  • Avoiding certain medications

As the disease progresses you may need dialysis or a kidney transplant.