Two other likely possibilities are asthma and an anxiety disorder.
Some people with asthma have cough and intermittent shortness of breath as their major symptoms. They may not hear wheezing. Contact your doctor.
Shortness of breath during a panic attack can feel quite severe and very scary. This often increases the anxiety level which perpetuates the shortness of breath. If you have not been previously diagnosed with panic disorder or hyperventilation from anxiety, you should call your doctor to discuss your symptoms.
Please continue with the guide to learn about causes of problems breathing that are more persistent.