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Asthma Health Center

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Asthma Glossary of Terms


Non-steroidal: anti-inflammatory medication that is not a steroid. Also see steroid.

Oxygen: the essential element in the respiration process to sustain life. This colorless, odorless gas makes up about 21% of the air.

Peak Expiratory flow rate: a test used to measure how fast air can be exhaled from the lungs.

Peak flow meter: a small hand-held device that measures how fast air comes out of the lungs when a person exhales forcefully. This measurement is called a peak expiratory flow (PEF) and is measured in liters per minute (lpm). A person's PEF may drop hours or even days before asthma symptoms are noticeable. Readings from the meter can help the patient recognize early changes that may be signs of worsening asthma. A peak flow meter can also help the patient learn what triggers his or her symptoms and understand what symptoms indicate that emergency care is needed. Peak flow readings also help the doctor decide when to stop or add medications.

Personal best peak expiratory flow (PEF): the highest peak flow number a person can achieve when symptoms are under good control. The personal best PEF is the number to which all other peak flow readings will be compared. In children, peak expiratory flow rates are based on how tall the child is. Therefore, the personal best peak expiratory flow will change as growth occurs. A child's personal best peak expiratory flow should be redetermined approximately every 6 months or when a growth spurt has occurred.

Pneumonia: an infection of the lung that can be caused by bacteria, a virus, or a mold..

Pollen: a fine, powdery substance released by plants and trees; an allergen.

Pollen and mold counts: a measure of the amount of allergens in the air. The counts are usually reported for mold spores and three types of pollen: grasses, trees, and weeds. The count is reported as grains per cubic meter of air and is translated into a corresponding level: absent, low, medium, or high.

Productive cough: a "wet" cough that may involve coughing up mucus.

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