You might think you’d know if you developed kidney disease. But in fact, 9 out of 10 people with kidney disease don’t know they have it. That’s because the disease can produce relatively few or mild symptoms until it reaches more advanced stages.

Because people over 65 are 38 percent more likely to develop kidney disease, it is important to be on guard for some of the more subtle signs. That is especially true if you have one or more of the following risk factors:

• • You smoke
  • You’re obese
  • You have a family history of kidney disease
  • You have diabetes
  • You have long-term high blood pressure

During the earliest stages of kidney disease, you might not experience any noticeable symptoms. However, routine lab tests might show higher levels of certain proteins in your urine. A Glomerular Filtration Rate test, a simple blood test, might show that your kidneys are having trouble filtering out waste. Therefore, it’s very important to keep up with regular physicals and undergo any lab tests recommended by your primary care physician.

In the third stage of kidney disease, subtle signs do sometimes appear. You might experience swelling in your hands or feet, changes in your urination, and anemia.

By stage four of kidney disease, back pain, more changes in urination, increased swelling in extremities, fatigue, and difficulty concentrating might appear.

And by the fifth stage of kidney disease, you might experience itchiness, insomnia, muscle cramps, and loss of appetite. Your urine might take on a “foamy” appearance.

Advanced kidney disease can also contribute to heart disease and stroke, making earlier detection even more important.

Many people continue to live relatively comfortable lives for years while undergoing kidney dialysis treatments for kidney disease. But of course, we all hope to never reach that stage. If you’re at increased risk of kidney disease, talk to your doctor about different ways to detect it early or ward off development of the disease entirely.