Heart failure is characterized by the heart’s inability to pump an adequate supply of blood to the body. Without sufficient blood flow, all major body functions are disrupted. Heart failure is a condition or a collection of symptoms that weaken your heart.

In some people with heart failure, the heart has difficulty pumping enough blood to support other organs in the body. Other people may have a hardening and stiffening of the heart muscle itself, which blocks or reduces blood flow to the heart.

Heart failure can affect the right or left side of your heart, or both at the same time. It can be either an acute (short-term) or chronic (ongoing) condition.

In acute heart failure, the symptoms appear suddenly but go away fairly quickly. This condition often occurs after a heart attack. It may also be a result of a problem with the heart valves that control the flow of blood in the heart.

In chronic heart failure, however, symptoms are continuous and don’t improve over time. The vast majority of heart failure cases are chronic.

About 5.7 million Americans have heart failure, according to the Centers for Disease Control and Prevention. Most of these people are men. However, women are more likely to die from heart failure when the condition goes untreated.

Heart failure is a serious medical condition that requires treatment. Early treatment increases your chances of long-term recovery with fewer complications. Call your doctor right away if you’re having any symptoms of heart failure.

Left-sided heart failure is the most common type of heart failure.

The left heart ventricle is located in the bottom left side of your heart. This area pumps oxygen-rich blood to the rest of your body.

Left-sided heart failure occurs when the left ventricle doesn’t pump efficiently. This prevents your body from getting enough oxygen-rich blood. The blood backs up into your lungs instead, which causes shortness of breath and a buildup of fluid.

Diastolic heart failure occurs when the heart muscle becomes stiffer than normal. The stiffness, which is usually due to heart disease, means that your heart doesn’t fill with blood easily. This is known as diastolic dysfunction. It leads to a lack of blood flow to the rest of the organs in your body.

Diastolic heart failure is more common in women than in men.

The right heart ventricle is responsible for pumping blood to your lungs to collect oxygen. Right-sided heart failure occurs when the right side of your heart can’t perform its job effectively. It’s usually triggered by left-sided heart failure. The accumulation of blood in the lungs caused by left-sided heart failure makes the right ventricle work harder. This can stress the right side of the heart and cause it to fail.

Right-sided heart failure can also occur as a result of other conditions, such as lung disease. According to the Mayo Clinic, right-sided heart failure is marked by swelling of the lower extremities. This swelling is caused by fluid backup in the legs, feet, and abdomen.

Systolic heart failure occurs when the heart muscle loses its ability to contract. The contractions of the heart are necessary to pump oxygen-rich blood out to the body. This problem is known as systolic dysfunction, and it usually develops when your heart is weak and enlarged.

Systolic heart failure is more common in men than in women.

Both diastolic and systolic heart failure can occur on the left or right sides of the heart. You may have either condition on both sides of the heart.

To diagnose heart failure, your doctor will take a careful medical history, review your symptoms and perform a physical examination. Your doctor will also check for the presence of risk factors, such as high blood pressure, coronary artery disease or diabetes.

Using a stethoscope, your doctor can listen to your lungs for signs of congestion. The stethoscope also picks up abnormal heart sounds that may suggest heart failure. The doctor may examine the veins in your neck and check for fluid buildup in your abdomen and legs.

After the physical exam, your doctor may also order some of these tests:

Your doctor may recommend including palliative care in your treatment plan. Palliative care is specialized medical care that focuses on easing your symptoms and improving your quality of life. Anyone who has a serious or life-threatening illness can benefit from palliative care, either to treat symptoms of the disease, such as pain or shortness of breath, or to ease the side effects of treatment, such as fatigue or nausea.

It's possible that your heart failure may worsen to the point where medications are no longer working and a heart transplant or device isn't an option. If this occurs, you may need to enter hospice care. Hospice care provides a special course of treatment to terminally ill people.

Hospice care allows family and friends — with the aid of nurses, social workers and trained volunteers — to care for and comfort a loved one at home or in hospice residences. Hospice care provides emotional, psychological, social and spiritual support for people who are ill and those closest to them.

Although most people under hospice care remain in their own homes, the program is available anywhere — including nursing homes and assisted living centers. For people who stay in a hospital, specialists in end-of-life care can provide comfort, compassionate care and dignity.

Although it can be difficult, discuss end-of-life issues with your family and medical team. Part of this discussion will likely involve advance directives — a general term for oral and written instructions you give concerning your medical care should you become unable to speak for yourself.