According to the American Geriatrics Society, breathing problems such as shortness of breath, discomfort in chest, coughing and wheezing, often have causes in underlying illnesses. These respiratory illnesses include chronic bronchitis, asthma and pulmonary emphysema as reported by National Jewish Health.

Chronic obstructive pulmonary disease, or COPD, is a progressively worsening disease that causes difficulty breathing.

A pulmonary embolism is a blood clot or other material lodged in your lung artery, according to MayoClinic.com. Usually, blood clots in the lungs result when clots located in deep leg veins break off and travel to the lungs.

Deep breathing can release stress and provide other noticeable health benefits. You will likely feel calmer after performing deep breathing exercises, and may trade feelings of anger or fear for a focused, relaxed state of mind.

The interior lining of the lungs contains very few pain receptors. However, the surrounding tissue and outer lining can feel pain. That's why lung pain after exercise may be related to issues elsewhere in your chest cavity, including your heart.

While asthma is a lung disease that causes breathing difficulty, it is often part of a larger syndrome called atopy. This term refers to an increased tendency to develop allergic reactions.

If your child has been battling a flu-like illness, you may be concerned if it suddenly gets worse when you thought it was getting better. Pneumonia, which is a serious infection of the lungs, often begins after an upper respiratory infection such as a cold or the flu.

Pollution from car exhaust, factory emissions, fuel combustion and other sources can hang a brown cloud over some cities. Air pollution not only contributes to respiratory diseases in humans and damages buildings, it can also affect plants. The effects of air pollution on plants develop over time and can't be undone.

According to the Mayo Clinic, asthma is a disease characterized by constricting airways, swelling and mucus production in response to environmental triggers. The National Institutes of Health classifies asthma based on four stages created to help health-care practitioners treat asthma.

Air purifiers and humidifiers have different functions. Air purifiers are clean indoor air, but do nothing for indoor humidity levels. They remove dust and smoke from the air, as well as allergenic substances like animal dander and pollen. Humidifiers add water into the air, but do not clean it.

Pulmonary nodules are round spots less than 3 cm in diameter, or a little over 1 inch. Seen in the lungs on chest X-rays or CT scans, pulmonary nodules appear on around one in 500 X-rays, the University of Rochester reports.

Most health-focused organizations will affirm that exercise is a vital part of your health. The American Heart Association recommends exercising or engaging in some type of physical activity for a minimum of 30 minutes per day for at least five days.