High blood pressure — also called hypertension — is the common link between kidney disease and heart disease.

High blood pressure also forces the heart to work too hard, which weakens it over time and can lead to heart failure.

In addition to damaging the coronary arteries, high blood pressure also harms the tiny arterial vessels that feed blood to the kidneys. These arteries are so small that they are easily damaged.

Diabetes is a kidney-killer because it plugs up the kidney’s tiny nephrons, or filters, rendering them useless.

What makes this even worse is that the kidneys have a system that can sense when a blood flow problem is occurring.

If it senses low blood flow, the kidneys respond by raising the blood pressure, which makes the problem even worse.

In addition to filtering and eliminating waste, the kidneys also maintain the body’s balance between sodium and fluid.

If the kidneys begin to fail, this balance can be thrown off, causing fluid to back up in the blood vessels.

This, in turn, makes the kidneys work harder and weakens them. Fluid buildup also increases the workload on the heart, making it weaker as well.

This is why kidney failure and heart failure occur together, and make each other worse.

Kidney disease leads not only to heart failure, but other serious health threats, including:

• Atherosclerosis, the disease process that causes coronary heart disease

• Irregular heartbeats or arrhythmias

• Anemia, a disease in which the body fails to make enough oxygen-carrying red blood cells, leading to fatigue and weakness