The National Kidney Foundation notes that more than 37 million American adults are living with kidney disease, and the majority don’t even know it [1]. One of the most effective ways to keep an eye on your kidneys performance is by understanding your kidney health and function.

Normal kidney function typically involves:

  • Filtering waste products
  • Balancing bodily water-salt ratio
  • Regulating blood pressure
  • Regulating red blood cell production
  • Regulating acid levels

See also: Can Medication Damage Your Kidneys?

What is normal kidney function?

Since many of those living with kidney disease don’t experience signs or symptoms until the disease has progressed, understanding normal kidney function is vital to understanding your kidney health.

From the filtering of waste products to the water balance in the body - the kidneys perform many crucial functions. Some of the kidneys key functions include:

  • Filtering Waste Products
    The kidneys filter out toxins, excess salt, urea, and waste products by flushing them out of the body with urine. If the body’s waste products build-up, it can lead to kidney disease[2].

  • Balancing Bodily Water-Salt Ratio
    Your kidneys are one of the body’s primary ways of maintaining a stable salt-water balance. It does this by releasing excess sodium in urine and by actively retaining or releasing water out of the body.

  • Regulating Your Blood Pressure
    If blood pressure is low, the kidneys produce a protein called angiotensin and a hormone called renin - both work together to constrict the vessels and bring your blood pressure to a more stabilised level[3].

  • Regulating Red Blood Cell Production
    The kidneys regulate red blood cells by producing a hormone called erythropoietin (EPO). The kidneys increase the production of EPO as soon as there’s a shortage of red blood cells in the tissues in order to regulate red blood cell production[4].

  • Regulating Acid Levels
    In response to increased acidity in the body, the kidneys attempt to secrete more hydrogen and generate more bicarbonate to regulate the body's acidity levels and ensure PH levels are balanced.

See also: What is Kidney Disease? Symptoms and Causes

What is normal kidney function level?

When it comes to finding out more about your kidneys performance - a blood or urine test is usually the go to. The test commonly tests for eGFR (estimated glomerular filtration rate); this is a simple calculation to determine how well your kidneys are filtering blood.

The below numbers from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), show what’s considered ‘normal’ and what might be looking further into:

  • eGFR of 60 or higher is in the normal range
  • eGFR below 60 may mean kidney disease
  • eGFR of 15 or lower may mean kidney failure

See also: Can too Much Protein Damage Your Kidneys?

Should you check your kidney function?

If you’re concerned about symptoms that you’re experiencing, it’s important to make a trip to your doctor for a check-up.

If you simply want to know a bit more about your kidney health, you have the option to take a kidney function test from the comfort of your own home. With LetsGetChecked’s Kidney Function Test you can monitor your kidney function and performance and receive your online results within 5 days.

You should consider taking a Kidney Function Test if any of the below are applicable to you:

  • You suffer from high blood pressure
  • You suffer from diabetes
  • You have suffered an acute injury
  • You have persistent urinary tract infections
  • You have kidney disease or a family history of one
  • You have kidney stones or a family history of them
  • You have a high protein diet
  • You have been taking performance-enhancing drugs

See also: How do You Check Your Kidney Function From Home?


  1. National Kidney Foundation. 10 signs you may have kidney disease. Online:
  2. Beaumont Hospital Kidney Centre. The Urinary System. Online:
  3. You and Your Hormones. Angiotensin. Online:, 2019
  4. You and Your Hormones. Kidneys. Online:, 2019
  5. You and Your Hormones. Kidneys. Online:, 2019