What causes chronic kidney disease?

The two main causes of chronic kidney disease are diabetes and high blood pressure, which are responsible for up to two-thirds of the cases. Diabetes happens when your blood sugar is too high, causing damage to many organs in your body, including the kidneys and heart, as well as blood vessels, nerves and eyes. High blood pressure, or hypertension, occurs when the pressure of your blood against the walls of your blood vessels increases. If uncontrolled, or poorly controlled, high blood pressure can be a leading cause of heart attacks, strokes and chronic kidney disease. Also, chronic kidney disease can cause high blood pressure.

Other conditions that affect the kidneys are:
·Glomerulonephritis, a group of diseases that cause inflammation and damage to the kidney's filtering units. These disorders are the third most common type of kidney disease.
·Inherited diseases, such as polycystic kidney disease, which causes large cysts to form in the kidneys and damage the surrounding tissue.
·Malformations that occur as a baby develops in its mother's womb. For example, a narrowing may occur that prevents normal outflow of urine and causes urine to flow back up to the kidney. This causes infections and may damage the kidneys.
Lupus and other diseases that affect the body's immune system.
·Obstructions caused by problems like kidney stones, tumors or an enlarged prostate gland in men.
Repeated urinary infections.

A number of conditions can cause permanent damage to the kidneys and/or affect the function of the kidneys and lead to CKD. Three common causes in the UK, which probably account for about 3 in 4 cases of CKD in adults, are:
·Diabetes. Diabetic kidney disease is a common complication of diabetes.
·High blood pressure. Untreated or poorly treated high blood pressure is a major cause of CKD. However, CKD can also cause high blood pressure, as the kidney has a role in blood pressure regulation. About nine out of ten people with CKD stages 3-5 have high blood pressure.
·Ageing kidneys. There appears to be an age-related decline in kidney function. About half of people aged 75 or more have some degree of CKD. In most of these cases the CKD does not progress beyond the moderate stage unless other problems of the kidney develop, such as diabetic kidney disease.

There are various other less common conditions that can cause CKD.