Fatigue, shortness of breath and dizziness occur with a wide range of medical disorders primarily affecting the cardiovascular system.

Shortness of breath can range from the merely uncomfortable to the potentially dangerous. If you have found yourself gasping for breath after climbing a few flights of stairs, or while carrying heavy packages, you may simply be out of shape.

Experiencing shortness of breath when walking or biking is likely caused by one of two things. You may reach your natural threshold for physical exertion, which leads to a shortness of breath.

Blood carries oxygen to every cell in your body to allow them to live and function properly. Low blood oxygen levels -- known as hypoxemia -- typically refer to an oxygen level in your arteries less than 80 millimeters of mercury (mm Hg).

Vitamins regulate multiple aspects of your health, and an insufficiency in any of the several essential vitamins has adverse health effects. One possible sign of a vitamin insufficiency is shortness of breath, which can develop due to a number of vitamin deficiency related-disorders.

Shortness of breath on exertion has many possible causes. Most commonly it is due to problems with the lungs, airways or heart. Other problems may cause shortness of breath on exertion as well.

Having shortness of breath is an extremely scary symptom that can be fatal, according to Cancerpage.com. Shortness of breath, in addition to wheezing, can be a side effect of many drugs, thus canceling out the effects of the drug.

A heartbeat consists of a two-part pump action that takes less than one second, according to the Texas Heart Institute. Normally, the heart follows a distinct beating pattern that properly sends blood through the blood vessels and supplies the body tissues with oxygen.

Shortness of breath while laying down -- a symptom medical professionals call orthopnea -- is concerning as it often suggests the presence of a serious underlying disease. Orthopnea can result from disorders of the heart, lungs and gastrointestinal system. It can also occur with obesity.

Your child's stuffy nose and mild cough can travel downwards through the respiratory system and transform into a chest cold in no time. The congestion and breathing difficulties that are often symptoms of a chest cold might be scary, but in most cases are manageable at home.

Shortness of breath, or dyspnea, may cause you to feel that you can't get enough air in your lungs, or that you are suffocating. You may also experience a tightening sensation in your chest.

Shortness of breath is a common symptom of asthma, but in some cases, allergies can cause asthma-like symptoms. Allergic rhinitis, hay fever and the body’s response to exercise can all result in shortness of breath.