Blood pressure is the force of blood pushing against blood vessel walls as your heart pumps out blood. High blood pressure NIH external link, also called hypertension, is an increase in the amount of force that blood places on blood vessels as it moves through the body.

Anemia is a condition in which your blood has a lower-than-normal amount of red blood cells or hemoglobin. Hemoglobin is the iron NIH external link-rich protein that allows red blood cells to carry oxygen from your lungs to the rest of your body. With fewer red blood cells or less hemoglobin, your tissues and organs—such as your heart and brain—may not get enough oxygen to work properly.

• When you have kidney disease, extra fluid and sodium in your circulation may cause edema. The edema associated with kidney disease usually occurs in your legs and around your eyes.
• Kidney damage. Damage to the tiny, filtering blood vessels in your kidneys can result in nephrotic syndrome. In nephrotic syndrome, declining levels of protein (albumin) in your blood can lead to fluid accumulation and edema.

Many diseases affect kidney function by attacking the glomeruli, the tiny units within the kidney where blood is cleaned. Glomerular diseases include many conditions with a variety of genetic and environmental causes, but they fall into two major categories:

• Glomerulonephritis describes the inflammation of the membrane tissue in the kidney that serves as a filter, separating wastes and extra fluid from the blood.
• Glomerulosclerosis describes the scarring or hardening of the tiny blood vessels within the kidney.

Although glomerulonephritis and glomerulosclerosis have different causes, they can both lead to kidney failure.

Kidney stones are hard, pebble-like pieces of material that form in one or both of your kidneys when high levels of certain minerals are in your urine. Kidney stones rarely cause permanent damage if treated by a health care professional. Kidney stones vary in size and shape. They may be as small as a grain of sand or as large as a pea. Rarely, some kidney stones are as big as golf balls. Kidney stones may be smooth or jagged and are usually yellow or brown. A small kidney stone may pass through your urinary tract on its own, causing little or no pain. A larger kidney stone may get stuck along the way. A kidney stone that gets stuck can block your flow of urine, causing severe pain or bleeding.

Source: https://www.niddk.nih.gov/health-information/urologic-diseases/kidney-stones/definition-facts