Blood is responsible for delivering oxygen throughout your body. So when your blood flow becomes impaired, your tissues don't get the oxygen they need. Your body tries to compensate for the shortfall by increasing your breathing rate to get more oxygen into your blood. This is one reason for shortness of breath, a common CHF symptom. But breathing harder doesn't help because your heart can't move blood around your body very well.

That brings up another problem associated with CHE When your heart pumps inefficiently, it can't pump well enough to power your blood's return trip from your tissues. Instead, blood backs up in your veins and collects in your tissues, a process known as congestion. (This is the "congestive" in congestive heart failure.) Blood collects in your lungs, further aggravating shortness of breath and possibly causing a persistent cough. Fluid also pools in areas farthest from your heart, especially in your ankles and feet. This is why swollen ankles are a common CHF symptom.

Impaired blood flow also affects your kidneys. As circulation becomes sluggish, your kidneys can't eliminate excess fluid as they should. The built-up fluid increases congestion and aggravates swelling.

In addition to shortness of breath, fluid retention, and swelling, CHF can cause an irregular heartbeat by interfering with your heart's electrical circuitry. An irregular heartbeat, or arrhythmia, can be serious and should be monitored by a doctor.

Despite its severity, CHF isn't all that well-known. It certainly hasn't gotten the same publicity as coronary heart disease. Yet this condition is surprisingly common. By one estimate, it affects some five million Americans. Most of these people are over age 75, the population for which CHF risk is highest. The condition is almost unheard of in people under age 45.

CHF most often occurs because of damaged heart valves. Normally, a valve momentarily closes between pumps in order to prevent the blood from flowing backward. When the valve is damaged, it doesn't close properly, and the blood doesn't circulate through the heart efficiently. This leads to congestion. Other common reasons for the development of CHF are functional flaws within the heart caused by previous heart attacks, birth defects, or infections. Atherosclerosis, a condition characterized by the hardening and narrowing of the arteries, can playa central role in worsening any of these conditions and can cause CHF.

Atherosclerosis also elevates blood pressure. And high blood pressure contributes to CHF by making the heart work harder than normal. In fact, about three-quarters of people who develop CHF have high blood pressure.

Other factors can raise your risk of developing CHF These include a high salt intake, certain nutritional deficiencies, kidney or liver disease, and emotional stress.

Treatment for CHF depends on the seriousness of the condition. If you have only mild to moderate symptoms, you may be able to manage them with home care under an M.D.'s supervision. But for more severe CHF, there is no substitute for aggressive treatment with mainstream medications, says naturopath Donald Brown, N.D., professor of herbal medicine at Bastyr University in Kenmore, Washington. If you've been diagnosed with congestive heart failure, you should definitely be under an M.D.'s care. And you should stick with any treatment program that your doctor prescribes.

That said, certain natural and alternative remedies may enhance the effectiveness of any therapies your doctor recommends. Here's what the experts say can help.