Chronic kidney disease (CKD) usually develops when a health condition or ongoing damage affects the kidneys for at least three months. In adults, the most common causes are diabetes and high blood pressure. Other causes include diseases that inflame the kidney filters, inherited conditions such as polycystic kidney disease, repeated infections, urine-flow blockages, severe kidney injury, and certain medicines. Identifying the cause helps guide evaluation and care.
The Two Main Causes of Chronic Kidney Disease in Adults
The kidneys filter waste and extra fluid from the blood while helping regulate blood pressure and maintain the body's balance of minerals and fluids. Chronic damage can interfere with these functions over time. In adults, diabetes and high blood pressure are the two leading causes of CKD, although other medical conditions can also damage the kidneys.
1. Diabetes
Diabetes can damage the kidneys when blood sugar levels remain high over time. Each kidney contains millions of tiny filtering units that help remove waste from the blood. High blood sugar can injure the small blood vessels and filters within the kidneys, gradually reducing their ability to work properly. Damaged filters may also allow protein to leak into the urine.
Kidney disease related to diabetes can develop gradually over many years. It can occur in people with type 1 or type 2 diabetes, and the risk is higher when blood sugar or blood pressure is not well controlled. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) identifies diabetes as one of the most common causes of CKD in adults.
2. High blood pressure
High blood pressure, also called hypertension, can damage the small blood vessels that supply the kidneys. When these vessels are damaged, the kidneys may become less effective at removing waste and extra fluid from the body. This damage can develop gradually, particularly when high blood pressure remains uncontrolled for a long time.
The relationship works in both directions. Damaged kidneys may retain extra fluid, which can raise blood pressure further and contribute to additional kidney damage. According to the NIDDK's guidance on high blood pressure and kidney disease, hypertension can be both a cause and a result of kidney disease. Managing blood pressure is therefore an important part of protecting kidney health.
What Other Conditions Can Cause Chronic Kidney Disease?
Several other diseases and physical problems can damage kidney tissue or interfere with normal kidney function. The NIDDK's overview of CKD causes includes immune system disorders, diseases affecting the kidney filters, inherited conditions, infections, certain blood disorders, and complications involving other organs.
- Glomerular diseases: The glomeruli are tiny filtering structures inside the kidneys. Conditions such as glomerulonephritis and IgA nephropathy can damage these filters and interfere with their ability to remove waste from the blood.
- Autoimmune diseases: Conditions such as systemic lupus erythematosus can affect the kidneys when the immune system attacks the body's own tissues. Kidney inflammation related to these diseases may lead to lasting damage.
- Inherited kidney disorders: Polycystic kidney disease and certain rare genetic conditions can cause kidney damage over time. An inherited condition may affect several members of the same family, although the pattern varies by disorder.
- Kidney infections: Certain infections can injure kidney tissue. Repeated or complicated kidney infections may contribute to chronic damage, particularly when underlying urinary tract problems are also present.
- Blockages in the urinary tract: Repeated kidney stones, an enlarged prostate, or other problems that obstruct the flow of urine can damage the kidneys. In some conditions, urine can also flow backward toward the kidneys.
- Acute kidney injury: A sudden episode of kidney damage, sometimes associated with severe illness or another serious medical problem, can have lasting effects. Acute kidney injury is not the same as CKD, but it is among the recognized causes that may contribute to chronic kidney problems.
- Heart, liver, and certain blood disorders: Conditions affecting other organs or the blood can interfere with kidney function or directly damage kidney tissue in some cases.
Can Medicines Contribute to Chronic Kidney Disease?
Yes. Long-term, regular use of certain medicines can contribute to kidney damage. The National Health Service (NHS) lists lithium and non-steroidal anti-inflammatory drugs (NSAIDs), a group of medicines used to relieve pain and inflammation, among possible contributors to CKD when used regularly over a long period.
This does not mean that everyone who takes these medicines will develop kidney disease. The risks depend on the medicine and the person's medical circumstances. People with existing kidney problems or concerns about their kidney function should ask a doctor or pharmacist to review their medicines. Prescribed treatment should not be stopped or changed without appropriate medical advice.
Which Risk Factors Make Kidney Disease More Likely?
Some factors increase the likelihood of developing CKD without necessarily being the direct cause of kidney damage in every person. The U.S. Centers for Disease Control and Prevention (CDC) identifies heart disease, family history, and overweight or obesity among the risk factors associated with chronic kidney disease.
- Heart disease or heart failure: Heart problems can be associated with reduced blood flow to the kidneys, increasing the risk of kidney dysfunction.
- Overweight or obesity: Excess body weight can increase the likelihood of developing high blood pressure and type 2 diabetes, which are major causes of CKD.
- Family history of kidney disease: Having a close relative with CKD can increase a person's risk, especially when an inherited kidney disorder is involved.
Having one or more risk factors does not mean that kidney disease will definitely develop. Likewise, CKD can occur in people who do not have the best-known risk factors. The underlying medical history and the pattern of kidney changes help determine which causes are most relevant in an individual case.
Do the Causes of Chronic Kidney Disease Differ in Children?
Yes. The causes of kidney disease in children differ from the most common causes in adults. The NIDDK's information on kidney disease in children identifies birth defects affecting the urinary tract, inherited diseases, infections, nephrotic syndrome, systemic diseases, trauma, and urine blockage or reflux among possible causes.
Some children are born with structural differences affecting their kidneys or urinary tract, while others develop kidney disease because of inherited conditions or diseases that damage the kidney filters. Diabetes and high blood pressure can also be relevant in children, but they are not the only causes considered. When a child may have kidney disease, assessment should take their age, medical history, development, and test results into account.
Can More Than One Condition Cause Kidney Damage?
Yes. Chronic kidney disease can result from a combination of medical problems rather than one isolated cause. For example, a person may have both diabetes and high blood pressure, with each condition contributing to kidney damage. An inherited kidney disorder can also coexist with another condition that affects kidney function.
Sometimes, the main cause is not immediately clear. Healthcare professionals consider the person's medical and family history, existing health conditions, and medicines when evaluating possible causes. Blood and urine tests can help assess kidney function and identify signs of damage, while imaging or other investigations may be appropriate in selected cases. Understanding the likely cause helps guide further evaluation and decisions about protecting the kidneys from additional damage.