What are the symptoms of heart failure?

Despite the name, heart failure does not mean the heart has failed completely. Instead, it means the heart isn't pumping efficiently enough to meet the body's need for blood.

When the body first detects that it's not getting an adequate blood supply, it tries to compensate. Stress hormones rise, pushing the heart to beat faster and harder. Blood vessels narrow in an effort to keep blood pressure stable. To keep blood flowing to the heart and brain, the body diverts blood away from less important tissues. The body also retains sodium and fluid in an attempt to supplement the volume of circulating blood.

In the short run, these fixes enable the heart to deliver a near-normal level of blood to the tissues. But over time, these compensatory measures can't keep up, and the heart weakens further.

The two sides of heart failure

Heart failure causes two major problems for the body: (1) the tissues and organs don't get enough oxygen, and (2) fluid builds up in the lungs and other tissues. Each of these spawns a series of problems. Lack of oxygen, for example, can lead to fatigue and mental confusion, while fluid buildup can cause weight gain and swelling in the feet and ankles. If you're unfamiliar with heart failure, you could easily interpret these as isolated symptoms. People often mistakenly attribute the early signs of heart failure to being out of shape, being overweight, or just getting old. Adding to the confusion is the fact that the symptoms can wax and wane over the course of the illness.

Heart failure can primarily involve just one side of the heart or both sides. The weaker side of the heart influences which early symptoms predominate:

• When heart failure mainly affects the left side of the heart, blood backs up into the lungs, causing shortness of breath and coughing.
• When mainly the right side is affected, blood backs up into the veins and builds up in body tissues, often leading to swelling in the legs.

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