Asthma Symptoms and Diagnosis

Common Symptoms of Asthma

The first step to successful prevention of asthma is to recognize the general symptoms of asthma caused by exposure to triggers. Sometimes the symptoms are so evident that a rapid asthma diagnosis can be made. The most common symptoms of asthma are:

• breathlessness
• tightness of the chest (often painless)
• wheezing (loudness varies from almost inaudible to very loud)
• sweating, increased pulse rate and anxiety (more pronounced in severe cases)
• bluish tint (cyanosis) to face, lips, mucous membranes (gums), and nail beds in acute attacks
• cough (due to the accumulation of phlegm/mucus in the lungs).

Unfortunately, many asthmatics will have symptoms before they are aware of them. A peak flow meter is a tool used to detect early asthma symptoms and monitor lung function as part of an asthma maintenance program.

The Peak Flow Meter

Lung doctors, or pulmonologists, recommend using a peak flow meter to measure the force of air expelled from the lungs. The possible asthmatic is instructed to take in a deep breath and then seal their mouth around the tube. Since the peak flow meter measures the force of air coming out of the lungs, the patient is asked to blow hard and fast into the tube. The device will measure and record a peak expiratory flow rate (PEFR). Peak flow rates should be measured in the following way:

• Each time you take a measurement, blow into the peak flow meter three times. Take the best value or highest number.
• Measure PEFR first thing in the morning and before going to bed at night when you are without symptoms of asthma. Record these numbers to find a "normal" peak flow rate.
• Get into the habit of measuring peak flow rates everyday. If the PEFR decreases it could be an early sign of an asthma attack. Many asthma attacks begin in the lower part of the lung and produce no noticeable symptoms.
• To assist your doctor, keep a personal asthma diary to record your peak flow rates and the details of instances when your symptoms become particularly aggravated.

Asthma Diagnosis Capabilities of the Peak Flow Meter

Doctors use the peak flow meter as a tool for asthma diagnosis and to evaluate the effectiveness of medication. Low peak flow rates suggest that bronchial tubes are collapsing when a person is trying to exhale. The doctor will then give the patient some inhaled medicine called a bronchodilator. After the medication has been inhaled, the patient will blow into the peak flow meter again. If the peak flow rate improves the doctor can predict that a degree of asthma exists.

Asthma Diagnosis with Spirometry Tests

For a more definitive asthma diagnosis, doctors will order a series of spirometry tests. The doctor directs the patient to blow into a tube using a number of different breathing techniques that allow lung volumes, flows and capacities to be measured. The test requires an effort for the patient and is not always the best asthma diagnosis tool for young children or individuals who are mentally incapable of following directions. On the positive side, spirometry provides the doctor with some strong asthma diagnosis information.

History and Physical for Asthma Diagnosis

The asthma diagnosis will also depend on a physical exam including the examination of nasal passages and listening to the lungs with a stethoscope. A history of prolonged cold symptoms, sinus infections or allergies can also signal the presence of asthma. Doctors take a detailed history and family history to determine if a hereditary link or possible exposure to triggers might contribute to symptoms of asthma.

Resources

American Academy of Allergy, Asthma and Immunology. (updated 2004). Tips to remember: What is a peak flow meter?

National Heart, Lung and Blood Institute. (nd). How is asthma diagnosed? NHLBI Diseases and Conditions Index.

National Jewish Medical and Research Center. (nd). Recognizing asthma signs and symptoms.

University of Pittsburgh Medical Center. (nd). Asthma.