The taller a person is the higher their peak flow. The highest peak flow reading for an individual occurs between the age of 30-40 years. A reading of 400- 600 l/min is considered normal. An individual suffering with asthma would have a lower reading of 200-400 l/min.

A peak flow meter allows you to measure day-to-day changes in your breathing.

Normal adult peak flow scores range between around 400 and 700 litres per minute, although scores in older women can be lower and still be normal. The most important thing is whether your score is normal for you.

Peak flow meter with few symptom questions can be effectively used in real-life clinical practice for objective detection of asthma and COPD, in absence of good quality spirometry.

80 to 100 percent of your usual or “normal” peak flow rate signals all clear. A reading in this zone means that your asthma is under reasonably good control.

If your airways are tight and inflamed, your peak flow score will be lower than normal. This could be a sign your asthma is getting worse.

If you notice a significant fall in your peak flow speed, it may be caused by a flare-up in your lung disease. People with asthma may experience low peak flow rates before they develop breathing symptoms.

To practice the pursed-lips breathing technique:

1. Inhale slowly through your nostrils.
2. Purse your lips, as if pouting or about to blow on something.
3. Breathe out as slowly as possible through pursed lips. This should take at least twice as long as it did to breathe in.
4. Repeat.

Though having both lungs is ideal, it is possible to live and function without one lung. Having one lung will still allow a person to live a relatively normal life. Having one lung might limit a person’s physical abilities, however, such as their ability to exercise.

Lung capacity or total lung capacity (TLC) is the volume of air in the lungs upon the maximum effort of inspiration. Among healthy adults, the average lung capacity is about 6 liters.

Normal Values of Pulmonary Function Tests

Spirometry tests are used to diagnose these conditions: COPD. asthma. restrictive lung disease (such as interstitial pulmonary fibrosis)…FEV1 measurement.

Abnormal results usually mean that you may have chest or lung disease. Some lung diseases (such as emphysema, asthma, chronic bronchitis, and infections) can make the lungs contain too much air and take longer to empty.

This represents the percentage of your lung capacity that you can expel in one second. The higher your percentage, the larger your lung capacity and the healthier your lungs. Your doctor will diagnose COPD if your FEV1/FVC ratio falls below 70 percent of the predicted value.

According to the Lung Institute, when an FEV1 value is less than 80 percent of an FVC, it indicates that an obstructive lung disease, such as COPD, is present.

COPD Stages

1. Stage 1: Mild. At this stage, you may not know you have COPD.
2. Stage 2: Moderate. At this stage, people have a cough, mucus, and shortness of breath.
3. Stage 3: Severe. Your lung function has seriously declined at this stage.
4. Stage 4: Very Severe. At this stage, you have very low lung function.

FEV1 measurement

Conditions that may be negatively impacted by the increases in myocardial demand or changes in blood pressure associated with spirometry: These include recent (< 1 week) myocardial infarction, systemic hypotension or severe hypertension, significant atrial/ventricular arrhythmia, noncompensated heart failure.

The normal value for the FEV1/FVC ratio is 70% (and 65% in persons older than age 65). When compared to the reference value, a lower measured value corresponds to a more severe lung abnormality.

The main criterion for COPD is a FEV1/FVC ratio <70%. Subclassification into mild, moderate, severe and very severe disease is achieved by including various levels of FEV1 as percentage of predicted value 2.

useful index of airflow limitation. The ratio FEV1/FVC is between 70% and 80% in normal adults; a value less than 70% indicates airflow limitation and the possibility of COPD. FEV1 is influenced by the age, sex, height, and ethnicity, and is best considered as a percentage of the predicted normal value.

If your FEV1/FVC ratio is decreased, this is consistent with an obstructive pattern. Usually, this diagnosis is reached if the FEV1/FVC is less than or equal to 70% in adults and less than 85% in children. 1 Damage to the airways and/or constriction of the airways is indicative of conditions such as: Asthma.

Outlook. Both asthma and COPD are long-term conditions that can’t be cured, but the outlooks for each differ. Asthma tends to be more easily controlled on a daily basis. Whereas COPD worsens over time.

The 6MWT is a tool for assessing people with COPD, and it can provide you important information either as one-time measure of your functional health or as a before-and-after measure to see how well a treatment plan is working.

The most common signs and symptoms of an oncoming exacerbation are: More coughing, wheezing, or shortness of breath than usual. Changes in the color, thickness, or amount of mucus. Feeling tired for more than one day.

Types of Asthma

• Adult-Onset Asthma.
• Allergic Asthma.
• Asthma-COPD Overlap.
• Exercise-Induced Bronchoconstriction (EIB)
• Nonallergic Asthma.
• Occupational Asthma.

Severe asthma, or brittle asthma, affects around 4% of all adults with asthma. Experts consider asthma to be severe when symptoms do not improve with standard medications. People with severe asthma are likely to: have more asthma attacks than people with mild-to-moderate asthma.

As your lungs continue to tighten during the asthma attack, you may be unable to use the peak flow meter at all. Gradually, your lungs may tighten so much during the asthma attack that there is not enough air movement to produce wheezing. This is sometimes called the “silent chest,” and it is a dangerous sign.

People with asthma often have other chronic and long-term conditions. This is called ‘comorbidity’, which describes any additional disease that is experienced by a person with a disease of interest (the index disease).