What is kidney disease?

Having kidney disease means that there is damage to your kidneys and they aren’t working as well as they should. Kidney disease is called “chronic” because kidney function slowly gets worse over time. Kidney disease leads to kidney failure, which is also called end-stage kidney disease. At this point, you’ll need dialysis (artificial filtering) or a kidney transplant.

What do your kidneys do?

You have two kidneys. They are bean-shaped organs that are located toward your back, on either side of your spine, just underneath the rib cage. Each kidney is about the size of your fist.

Your kidneys have many jobs, but their main job is to filter (clean) your blood, getting rid of toxins (wastes) and excess salt and water as urine. If your kidneys are damaged and don’t work as they should, wastes can build up in your blood and can make you sick. Your kidneys also balance the amount of salts and minerals in your body, make hormones that control blood pressure, make red blood cells and keep your bones strong.

Are there stages of chronic kidney disease?

Yes, there are five stages of kidney disease. The stages are based on how well your kidneys are able to do their job – to filter out waste and extra fluid from your blood. The stages range from very mild (stage 1) to kidney failure (stage 5). Healthcare providers determine the stage of your kidney function according to the glomerular filtration rate (GFR). Your GFR is a number based on the amount of creatinine, a waste product, found in your blood, along with other factors including your age, race and gender.

Stages of Chronic Kidney Disease
StageGFR* (ml/min)What it Means
Stage 190 and higherYour kidneys are working well but you have signs of mild kidney damage.
Stage 260 to 89Your kidneys are working well but you have more signs of mild kidney damage
Stage 330 to 59Your kidneys aren’t working as well as they should and you have moderately decreased kidney function. This is the most common stage. You may notice symptoms at this stage.
Stage 415 to 29You have poor kidney function; your kidneys are moderately to severely damaged.
Stage 5Less than 15Your kidneys are very close to failing or have failed. You need kidney dialysis or a kidney transplant.
*GFR = glomerular filtration rate

Who is at risk for chronic kidney disease?

Some 37 million people in the United States are living with chronic kidney disease. Anyone can get chronic kidney disease. You are more at risk for chronic kidney disease if you:

  • Have diabetes.
  • Have high blood pressure.
  • Have heart disease.
  • Have a family history of kidney disease.
  • Have abnormal kidney structure.
  • Are African-American, Hispanic, Native American or Asian.
  • Are over 60 years of age.
  • Have a long history of taking painkillers, including over-the-counter products such as aspirin and ibuprofen.

What causes kidney disease?

Kidney diseases happen when your kidneys are damaged and can’t filter your blood. The damage can happen quickly – when it’s caused by injury or toxins – or, more commonly, over months or years.

High blood pressure (hypertension) and diabetes are the two most common causes of chronic kidney disease. Other causes and conditions that affect kidney function and can cause chronic kidney disease include:

  • Glomerulonephritis. This type of kidney disease involves damage to the glomeruli, which are the filtering units inside your kidneys.
  • Polycystic kidney disease. This is a genetic disorder that causes many fluid-filled cysts to grow in your kidneys, reducing the ability of your kidneys to function.
  • Hypertensive nephrosclerosis. Kidney damage caused by chronic, poorly controlled hypertension.
  • Membranous nephropathy. This is a disorder where your body’s immune system attacks the waste-filtering membranes in your kidney.
  • Obstructions of the urinary tract from kidney stones, an enlarged prostate or cancer.
  • Vesicourethral reflux. This is a condition in which urine flows backward – refluxes – back up the ureters to the kidneys
  • Nephrotic syndrome. This is a collection of symptoms that indicate kidney damage.
  • Recurrent kidney infection (pyelonephritis).
  • Diabetic nephropathy. This is damage or dysfunction of one or more nerves, caused by diabetes, which typically results in numbness, tingling, muscle weakness and pain in the affected area.
  • Lupus and other immune system diseases that cause kidney problems including polyarteritis nodosa, sarcoidosis, Goodpasture syndrome and Henoch-Schonlein purpura.

What are the symptoms of chronic kidney disease?

In the early stages of kidney disease, you usually don’t have noticeable symptoms. As the disease worsens, symptoms may include:

  • A need to pee (urinate) more often.
  • Tiredness, weakness, low energy level.
  • Loss of appetite.
  • Swelling of your hands, feet and ankles.
  • Shortness of breath.
  • Blood in your urine; foamy urine.
  • Puffy eyes.
  • Dry and itchy skin.
  • Trouble concentrating.
  • Trouble sleeping
  • Numbness.
  • Nausea or vomiting.
  • Muscle cramps.
  • High blood pressure.
  • Darkening of your skin.

What are the complications of chronic kidney disease?

If your kidneys aren’t working properly, the rest of your body isn’t either. Some of the complications of chronic kidney disease include:

  • Low red blood cell count (anemia).
  • Weak and brittle bones.
  • Gout.
  • Metabolic acidosis. This is a chemical imbalance (acid-base) in your blood caused by decrease in kidney function.
  • High blood pressure.
  • Heart disease, including increased risk of stroke and heart attack.
  • High potassium (hyperkalemia), which affects your heart’s ability to function correctly.
  • High phosphorus (hyperphosphatemia).
  • Fluid buildup, leading to swelling in feet, ankles and hands; fluid in your lungs.
  • Erectile dysfunction, fertility problems.
  • Decreased immune response, increasing your risk of infection.

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