Question

Marie has been out of breath and feeling like she is going to pass out she is healthy for her age group- she is 17. Marie eats as healthy as she can. she has been tested for asthma and the results came back negative which means she doesn't have asthma, what could she have?

Answer 1

"Bird fancier's lung' (BFL) — and it can also be triggered by duvets made of duck and goose down. Symptoms of hypersensitivity pneumonitis, or bird fancier's lung, often go unnoticed for years because the changes are so subtle.Symptoms of hypersensitivity pneumonitis often go unnoticed for years because the changes are so subtle, explains Stephen Spiro, a professor of respiratory medicine at Royal Brompton and Harefield NHS Foundation Trust, and medical adviser to the British Lung Foundation. The condition nibbles away at the lungs and causes them to stiffen over a long period. 'The amount of allergen (in this case avian proteins) needed to cause damage to the lungs is tiny and it happens so slowly, over so many years, that typically people aren't diagnosed until the disease is quite advanced,' he says. 'It usually stops or slows if the bird is removed from the patient's home, but the lungs may be so damaged from past exposure that the full extent of damage is not noticed until it disrupts breathing.'It's not clear why some people develop hypersensitivity and others don't, or why only some people develop serious lung disease because of it." 
"The medical definition of shortness of breath is dyspnea, and it occurs when your teen isn't able to breath normally and feels like she can't get enough air. She might feel a tightness in her chest or feel like she's suffocating, according to MayoClinic.com. In some cases, shortness of breath is temporary and goes away when the environmental or lifestyle factors causing the shortness of breath are eliminated. In other cases, shortness of breath is caused by an underlying medical condition that must be treated to reduce symptoms.Extreme physical exertion can cause your teen to have a hard time breathing, but usually discontinuing the exercise will resolve the problem. Some teens experience shortness of breath if they visit areas that have a high elevation or that have very warm or very cold temperatures, according to Circulation, a journal by the American Heart Association. Having a cold that clogs your teen's sinuses can also make it more difficult to breathe, but the problem goes away as the virus clears up. Exposure to dust, cigarette smoke and environmental pollutants can also lead to temporary shortness of breath.If your teen's shortness of breath occurs often, it could signal the presence of an underlying medical condition. Asthma is a common problem among children and can cause difficulty breathing. Anemia can also cause shortness of breath. It occurs when your teen doesn't get enough iron, and the disorder can also cause fatigue and pale skin. Chronic allergies to dust, pollen and mold can also negatively impact your teen's ability to breathe. If your teen is obese, he might also become short of breath. Anxiety disorders, panic attacks, heart problems and lung disorders can also lead to shortness of breath."

http://www.dailymail.co.uk/health/article-3914592/Are-feeling-wheezy-want-change-duvet-rid-pet-bird-....... 
https://www.livestrong.com/article/560691-shortness-of-breath-in-teens/