Causes of Fatigue, Shortness of Breath and Dizziness

The combination of fatigue, shortness of breath and dizziness usually points to a problem involving the cardiovascular system, meaning the heart and circulatory system. In collaboration with the lungs, this system supplies the body tissues with oxygen as well as nutrients. It also enables removal of metabolic waste products. A significant problem in one or more components of the cardiovascular system can lead to fatigue, shortness of breath and dizziness usually due to reduced oxygen delivery to the brain and other body organs and tissues.

The heart contains 4 valves that control blood flow between the upper and lower heart chambers, and outflow from the lower heart chambers. Heart valve disorders that significantly impair blood flow through or out of the heart can lead to fatigue, shortness of breath and dizziness. Symptoms typically develop and worsen gradually. They usually occur due to insufficient oxygen delivery to the body or fluid leakage into the air sacs caused by increased lung circulation blood pressure, or both. Most heart valve disorders affect those of the left side of the heart. The mitral valve separates the left upper and lower heart chambers. The aortic valve controls flow from the lower left heart chamber into aorta, the body's largest artery.

Normal heart function depends on regular, coordinated contraction of the upper then the lower heart chambers. This process is regulated by a specialized electrical conduction system in the heart. Some intermittent and infrequent heart rhythm abnormalities, or arrhythmias, pose no serious health risk and cause no symptoms. Arrhythmias that compromise the amount of blood pumped by the heart, however, can lead to fatigue, shortness of breath and dizziness or fainting. This can occur if the heart beats too slowly or too rapidly. People with other heart problems, such as a prior heart attack or coronary artery disease, are at increased risk for serious arrhythmias.

According to a 2017 report from the American Heart Association, an estimated 6.5 million adults in the US have heart failure. With this condition, the heart cannot pump enough blood through the circulation to keep up with the body's demands in certain situations. Initially, this occurs only during strenous physical activity. As the condition progresses and the heart grows weaker, even ordinary activities cause shortness of breath and fatigue becomes more prominent. With advanced heart failure, symptoms occur with even minimal activity or might be present at rest. Dizziness when sitting up or standing can occur, which might be due to the heart condition itself or a side effect of medications used to treat it.

There are other possible causes of fatigue, shortness of breath and dizziness. Some examples include:

• Severe anemia
  
• Blood clot in a lung artery, or pulmonary embolism
• Inflammation of the heart sac, or pericarditis
• Infection of the heart lining, or infective endocarditis
• Pneumonia

Call your doctor as soon as possible if you experience shortness of breath, fatigue and dizziness. Seek immediate medical care if your shortness of breath is sudden, worsening or severe, or if you experience any warning signs or symptoms, including:

• Chest, neck, jaw or left arm pain
  
• Cold clammy skin or fever
• Sense of impending doom
• Coughing up bloody or foamy phlegm
• Racing or irregular pulse
• Fainting