Final answer:
PVFS differs from asthma in that it does not cause bronchospasm or airway obstruction, but rather manifests with fatigue, muscle pain, and cognitive issues that can worsen with exercise.
Step-by-step explanation:
The symptoms of Post-Viral Fatigue Syndrome (PVFS), which may be presumed as the question's reference to 'PVFD', contrast with those of asthma in several ways. While exercise can often exacerbate asthma symptoms, leading to difficulty breathing, coughing, wheezing, and chest tightness, PVFS primarily causes profound fatigue, muscle and joint pain, and neurological complaints such as cognitive dysfunction, which can worsen with physical or mental exertion.
Unlike asthma, PVFS does not typically result in bronchospasm or airway obstruction. In the context of asthma, an exacerbation is a period where symptoms become noticeably worse due to various triggers, including exercise, stress, and exposure to allergens or irritants like pollution. Asthma attacks involve acute inflammation of the airways, which can be visualized by swelling and narrowing in the lungs, coupled with excessive mucus production. In contrast, PVFS does not manifest with these acute airway changes but is rather distinguished by a state of chronic debilitation that persists after an initial viral infection, often regardless of environmental factors.