Kidneys: The Chemical Factories of the Human Body

The body is one complicated machine. Everything is connected. Everything works (or is supposed to, anyway) in harmony. Many times, when you're diagnosed with an illness, it’s important to address and treat it properly so other parts of your body aren’t affected.

Take the kidneys, for example. The kidneys, along with the liver, are our body’s cleaning department. According to the National Kidney Foundation,  these two, fist-sized organs help to remove toxins and waste from the body. But they also do a lot more. Along with getting rid of waste, your kidneys:

• Balance the body’s fluids
• Remove drugs from the body
• Control the production of red blood cells
• Produce a form of vitamin D that promotes strong, healthy bones
• Release hormones that regulate blood pressure

As you can probably tell from this list, the kidneys control important functions that help keep our bodies healthy. Unfortunately, they aren’t immune to disease.

Kidney Disease

When the kidneys are unable to function at their full capacity for longer than three months it's classified as chronic kidney disease. While some chronic kidney conditions run in the family, they are often caused by common conditions such as hypertension and diabetes.

Other conditions that can affect the kidneys include lupus and diseases that affect the immune system. Long-term use of over-the-counter medicine can also damage the kidneys.

Detecting Kidney Disease

There are easy tests people with a high risk of kidney disease can have done to check their kidney health. One test detects protein in the urine. The Albumin-to-Creatinine Ratio (ACR) test checks the amount of albumin in the urine. A high level of the protein may suggest that the filtering parts of the kidneys have been damaged. The test can be affected by exercise or a fever, so it’s important to tell your doctor before the test about any recent physical activity or any illness.

Another test — the Glomerular Filtration Rate (GFR) — measures how well the kidneys remove waste from the blood. It is the best way to check kidney function. A score over 90 is good, while a score of 60 to 89 indicates the kidneys should be monitored. A score of less than 60 for at least a period of three months indicates kidney disease.

People with an increased risk of kidney disease should have ACR and GFR tests done, including:

• People who are obese
• People who have heart disease
• People with diabetes
• People with high blood pressure (hypertension)
• People with a family member who has kidney disease
• People who are Black, Latino, Asian/Pacific Islander or American Indian

Preventing Kidney Disease

Since the kidneys are so important to our overall health, it’s important to keep them working well for as long as possible. Healthy choices and proactive steps now can protect your kidney function and help fend off many other diseases and serious health conditions.

• Keep blood sugar, blood pressure and cholesterol levels under control.
• Exercise regularly.
• Lose weight if you need to.
• Eat healthy foods.
• Avoid or limit alcohol.
• Take medicines as prescribed.
• Stop smoking.
• Talk to your doctor about any prescription or over-the-counter (OTC) drugs you take to make sure they’re safe for your kidneys.

For more information about kidney disease, visit the National Kidney Foundation. 

Sources: How Your Kidneys Work,  National Kidney Foundation; Chronic Kidney Disease,  Mayo Clinic, 2023; Microalbumin Creatinine Ratio,  Medline Plus, 2022; Glomerular Filtration Rate Test,  Medline Plus, 2023; Preventing Chronic Kidney Disease,  National Institute of Diabetes and Digestive and Kidney Diseases, 2016; Preventing Chronic Kidney Disease,  Centers for Disease Control and Prevention, 2024

Originally published 2/7/2017; Revised 2021, 2022, 2023, 2024