When you're hungry, your stomach lets out a growl or two. When you run around, your heart lets you know it's really working by boom, boom, booming! But some important body parts are quiet as a whisper. Psst — we're talking about your kidneys.
What Are the Kidneys?
Your kidneys are tucked under your lower ribs on either side of your spine. Each one is about the size of your fist and shaped like a bean. Most people have two kidneys, but they work so effectively that a person can be happy and healthy with only one.
Think that's cool? Check out their job: each day your kidneys act like high-powered filters for about 200 quarts (189 liters) of fluid in your flowing blood. That's enough fluid to fill 100 of those big soda bottles that hold 2 liters each!
How does the waste get in your blood? Well, your blood delivers nutrients to your body. Chemical reactions occur in the cells of your body to break down the nutrients. Some of the waste is the result of these chemical reactions. Some is just stuff your body doesn't need because it already has enough. The waste has to go somewhere; this is where the kidneys come in.
The kidneys send that stuff, along with excess water, on to the bladder as urine (pee), so you can get rid of it when you go to the bathroom.
Besides taking out your body's "trash," your kidneys help balance your body's water, salt, and mineral levels so your other organs and bones can do their best work. They help in the production of red blood cells and produce a form of vitamin D, which promotes healthy bones. If that's not enough, they help keep your blood pressure at a healthy level.
Kinds of Kidney Diseases
Like any complicated machine, not all kidneys work perfectly. When someone's kidneys have problems for a long time, doctors call it a chronic kidney disease. Children's kidney problems may be congenital (say: kun-JEH-neh-tul) or acquired (say: uh-KWIRED).
The difference is that a congenital problem exists from the day someone is born. An acquired kidney problem develops over time, often due to an injury, kidney infection, or other illness. Many kidney problems are hereditary, which means they're passed down through a person's genes.
How Are Kidney Diseases Diagnosed?
Kidney problems are often not noticed at an early stage. As the illness progresses, someone with a kidney disease may pee too much or too little, have blood in the urine, feel tired, nauseated, itchy, or dizzy. The person also might have puffy eyes, ankles, or feet because the body has trouble getting rid of extra fluid. Someone who has these problems needs to go to the doctor.
At a doctor visit, the doctor would examine the person and ask questions about past and current health problems. Doctors can use many special tests to find out if someone's kidneys are working properly. Blood pressure will be measured — if it's high, it may indicate a kidney problem. Because the kidneys produce urine, the doctor can check a person's pee for blood or protein.
The doctor also do a blood test to check the amount of something called creatinine (say: kree-AT-ih-neen), a natural waste product that muscles release into the blood; and blood urea nitrogen (BUN), which comes from the breakdown of protein in the foods we eat. The level of creatinine and BUN can go up too high if the kidneys aren't working well.
To try to see what is going on, the doctor might take pictures of the kidneys with X-rays, ultrasound scans, CT scans, or MRI scans. To pinpoint the problem, a doctor may also do a biopsy (say: BY-op-see). In this test, the doctor takes out a tiny piece of kidney tissue with a needle and looks at it under a microscope. Doctors and nurses will give medicine called anesthesia to keep the person comfortable during the biopsy.
How Do Doctors Treat Kidney Problems?
The treatment for chronic kidney problems depends on the cause and how well the kidneys are working. It may include diet changes, vitamins, minerals, and medications to help with growth and to prevent bone disease. Sometimes unhealthy kidneys have problems producing a hormone that helps make red blood cells, the cells that carry oxygen to your body's tissues.
When a person doesn't have enough red blood cells, that's called anemia, which can make someone feel worn out. If this is a problem, the doctor may prescribe blood transfusions or medicine that helps the body make red blood cells.
Kids with kidney problems are more likely to get high blood pressure, which can be harmful if it isn't controlled. In those cases, a kid may have to take blood pressure medicine.
For kidneys that need even more help, doctors might suggest dialysis (say: dye-AL-ih-sis), a process that cleans the blood artificially. A kidney transplant is another possibility. In this operation, doctors replace a kidney that doesn't work with a healthy kidney donated by another person.
What's Life Like for Kids With Kidney Problems?
Kids who have kidney problems are just like other kids, but they may have to take special medicine or go to the hospital for treatments, such as dialysis. They also will need to talk with their doctors about participating in sports, but often they can join in the fun. Some kids may need to avoid contact sports, such as football.
Kids with kidney illnesses also may need to talk with a doctor or dietitian about the foods they eat. Some kids won't have to follow any special diet, but others may need to avoid salty foods and limit the amount of fluid they drink. Potassium and protein also may be a concern for someone with a kidney disorder.
It's no fun to be sick, no matter the cause. But the good news for kids with kidney problems is that they can take steps to stay healthier and feel better, with a little help from their families and doctors.
Reviewed by: Mary L. Gavin, MD
Date reviewed: February 2014