| Some asthma symptoms are present in other | | | | as fast as possible. |
| conditions, such as coronary heart disease, bronchitis | | | | As you breathe out the speed of the air quickly |
| or emphysema. So breathing tests are used to | | | | reaches its peak, then drops off. The instrument |
| pinpoint asthma and eliminate other diseases from | | | | registers the fastest speed. There are inexpensive |
| the diagnosis. The two main devices for testing lung | | | | instruments and your family doctor will have one. You |
| function are the peak flow meter and the spirometer. | | | | can also but one for yourself and use it to monitor |
| If you have asthma your airways become narrowed | | | | your peak flow rate two or three times a day. The |
| so the air will not flow freely. | | | | peak flow meter is invaluable for warning you that |
| It is impossible to measure the diameter of the air | | | | your condition may be deteriorating. |
| passages, but this can be estimated by finding out | | | | Using this device regularly could save your life. The |
| the speed at which air is expelled from the lungs. The | | | | volume of air expelled by a healthy lung is between |
| peak flow meter, or peak expiratory flow meter, is a | | | | 400 and 600 liters per minute. In asthma rates of |
| small instrument that measures the maximum rate at | | | | between 200 and 400 liters are common and in |
| which you breathe out. You take a huge breath, | | | | severe attacks it could drop to 100 liters a minute or |
| inflating your lungs as far as you can, hold it for a | | | | lower. |
| couple of seconds, then force it out into the device | | | | |