Where are the kidneys?

Kidneys are internal organs that lie on the side of the spine in the lower back. Most people are born with two kidneys; each is about the size of a fist.

What do your kidneys do?

  • When healthy kidneys filter and clean the blood, waste products and excess water leave your body in the urine.
  • Kidneys contribute to good health by balancing the levels of different minerals, like sodium (salt), potassium, and phosphorus.
  • Kidneys release hormones to control blood pressure, make red blood cells, and keep your bones healthy.

Kidney in the body


What happens when your kidneys aren't working properly?

Many diseases, including diabetes and high blood pressure, can damage the kidneys. When the kidneys cannot do their usual jobs, harmful toxins and excess fluid build up in the body and can make you sick.

Most of the time, the kidneys do not stop working all at once. Chronic kidney disease (CKD) is a long-term health problem. For some people with CKD, the damaged kidneys eventually stop working altogether. This is called "kidney failure" or end-stage renal disease (ESRD). In some cases, there is acute damage to the kidneys that leads to sudden kidney failure.

What are the stages of Chronic Kidney Disease (CKD)?

CKD is divided into 5 stages. Each stage tells you how well the kidneys are working. Doctors often estimate kidney function based on the glomerular filtration rate (GFR), a test based on levels of creatinine (a waste product that is normally removed by the kidneys) in the blood. As kidney disease gets worse, GFR decreases. To explain how well your kidneys are working, their function can be described as a percentage of normal function. For example, when the kidneys are working normally, they can be described as working at 100%.

Stages of Kidney Disease

Many people don't have any signs and symptoms and learn they have kidney disease when it is advanced. When kidney function is very low, symptoms may include:

  • Changes in urination
  • Difficulty breathing
  • Swelling
  • Feeling tired and having less energy
  • Sleeping problems
  • Dry, itchy skin
  • Changes in appetite
  • Nausea or upset stomach
  • Muscle cramps
  • Sexual or intimacy issues
  • Trouble concentrating or thinking clearly
  • Memory loss/forgetfulness

It's important to remember that these symptoms can also be caused by other illnesses and are common as people age.

Experiences & StoriesI forget simple things that I used to remember. Like the other day, my wife asked me to stop and pick up milk on my way home, and I don't remember her asking at all. Sometimes I just feel foggy.

It is common for people with kidney failure to experience these feelings and emotions:

  • Shock
  • Fear
  • Depression
  • Mood swings
  • Irritability
  • Anxiety

How can people with advanced kidney disease take care of their health?

You may not be feeling well right now, but you will not feel like this forever. Although every day may be different, people starting dialysis often feel better day-by-day. There are also other ways you can take care of your overall health and well-being.

Health Tip   Health Tips
  • Take an active role in managing your kidney disease so that you can feel in-control.
  • Being an active participant in the choice of dialysis type will help you get the treatment that best fits your life.
  • Take steps to control your other health issues, like high blood pressure, diabetes, and heart disease.
  • Stay as active as you can. Exercising even a little bit can help improve overall health, increase energy, and reduce stress. Make small goals for yourself. For example, getting the mail could be an exercise goal for you.
  • Try to maintain your regular routine and do things you enjoy. For example, if you were working and had to temporarily leave your job because of kidney failure, you might make it a goal to return to work.

Experiences & StoriesIt's important to me that I find a way to get some kind of activity in the day. I started walking my dog down the street and back; it helps me get some fresh air.

Research described on this web site was partially funded through a Patient-Centered Outcomes Research Institute (PCORI) Award (1109). The statements and views presented here are solely the responsibility of the authors and do not necessarily represent the views of the Patient-Centered Outcomes Research Institute (PCORI), its Board of Governors or Methodology Committee.