Chlamydia pneumoniae is a common species of bacteria of the Chlamydia genus. Approximately 50 percent of Americans aged 20 and older have experienced a Chlamydia pneumoniae infection, and reinfection later in life seems common, notes the Centers for Disease Control and Prevention.

Certain irritants or allergies can trigger an asthma attack, which causes the airways of the bronchial tubes to constrict, resulting in extreme difficulty in breathing due to the inflammation and increased mucous produced by the lungs, according to MedlinePlus.

According to MedlinePlus.com, the average adult takes about 8 to 16 breaths each minute. Air enters your body through your nose and travels down your bronchial tubes and into your lungs. Phlegm works with your respiratory system, interacting with the air you breathe.

With the passage of so many new smoking bans and other smoking ordinances, there has been a new wave of publicity about the dangers of smoking. You may be aware that smoking is the second leading cause of death in the United States.

As humans ascend higher into the atmosphere, air density declines. While air composition remains similar, the drop in air pressure, and in return, air volume, effectively makes the respiratory system work much harder in order to supply the same levels of oxygen to the blood stream.

An upper respiratory infection can affect any of the breathing mechanisms of your head and chest, including the nose, throat and sinuses. In addition to difficulty breathing, you may experience a sore throat, nasal congestion, cough, watery eyes, headache and ear stuffiness as a result of this infection.

According to the U.S. Food and Drug Administration, Singulair is the brand name of a medication called montelukast. It is a leukotrine receptor antagonist that blocks leukotrines. These are chemicals that trigger an allergic response in the human body.

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.

If you have a burning sensation in your chest while walking on a treadmill, you’re likely experiencing symptoms of exercise-induced asthma. Exercise tends to trigger an attack for most chronic asthma sufferers, but in some cases, exercise is the only trigger.

Benign lung nodules are small, noncancerous masses of tissue typically discovered incidentally on a chest x-ray or CT scan. One out of every 500 to 1,000 chest x-rays reveals an unexpected lung nodule.

Air hunger is one of the most distressing of all medical symptoms. Patients who can't derive enough oxygen from the air they breathe typically suffer from this symptom. Oxygen therapy involves supplying an increased concentration of oxygen to the lungs, helping alleviate breathlessness.

Hyperventilation is defined as rapid breathing. The normal breathing rate is 14 to 18 breaths per minute. Carbon dioxide is the gas that normally regulates the rate of breathing. A rapid rate of breathing can occur normally after exercise.