With a high reading, doctors can tell that an inflammation is present and that treatment with cortisone should help reduce the swelling and relieve the asthma symptoms.
This suggests that if a person is suffering from symptoms, an inflammation isn’t the likely cause. If cortisone is already being taken, a normal NO reading means that the inflammation is under control. However if symptoms are still present, the doctor needs to review the diagnosis as it may not be asthma after all.
This can be taken as an early sign that an asthma attack is about to happen or as a sign that the cortisone medication has not been taken properly.
This confirms that treatment is working effectively.