Understanding Kidney Disease -- the Basics

Diabetes (types 1 and 2) and high blood pressure are the most common causes.
Immune system diseases, such as lupus, and long-term viral illnesses, such as HIV/AIDS, hepatitis B, and hepatitis C, can also cause problems.
Urinary tract infections within the kidneys themselves, called pyelonephritis, can lead to scarring as the infection heals. Multiple episodes can lead to kidney damage.
You could have inflammation in the tiny filters (glomeruli) within your kidneys. This can happen after a strep infection.
Polycystic kidney disease, where fluid-filled cysts form in your kidneys, is the most common type of inherited kidney disease.
Defects present at birth are often the result of a urinary tract obstruction or malformation that affects the kidneys. One of the most common involves a kind of valve between the bladder and urethra. These defects, sometimes found while a baby is still in the womb, can often be repaired with surgery by a urologist.

Drugs and toxins, including long-term use of some medications, such as NSAIDs (nonsteroidal anti-inflammatory drugs) like ibuprofen and naproxen, and intravenous "street" drugs can permanently damage your kidneys. So can being around certain chemicals over time.