This may or may not be classic sick building syndrome (SBS). However your and your friend are almost certainly responding to some material in her home, such as a building material or an organic material like mold or cat dander from the previous occupant. She should report this to the state health department. She should also ask if they could recommend an industrial hygienist to check her apartment. It is irrelevant that she doesn't see mold. It could be in the walls or the ventilation system.
She should get out of the apartment until this can be resolved. Also she should ask if any of her neighboring apartment dwellers have experienced similar symptoms.
There are some test you can buy at like home depot for mold and rayon(i believe thats only for homes?) They are about 20.00 each, you may have to mail them out, no chance of her moving again??
She has asked for a different unit but none are available right now.
Hi...chronic mold exposure can permanently damage your lungs and cause other serious health problems. There are hundreds of articles about it on the net, look up "chronic mold exposure". Mold "hides" and doesn't always smell...we couldn't see OR smell the mold infestation in our home but I was desperately ill for 3 months, with constant, gasping for air asthma-like attacks last summer, while we ran the air conditioner. Later we found, under the wall panelling where the AC had leaked water, a wall of Aspergillus fungus 4 foot tall and 6 foot wide. That's more than enough mold to cause serious health problems. Have her look into dark areas, under sinks, inside of closets, places where rain may have leaked in thru a window, check in the basement. If the apartment is mold infested she needs to get it cleaned up or move out. Cleaning it can be very dangerous for your lungs and very expensive to hire it done. You can buy rubber gloves, masks, goggles etc. There are good articles on the net about how to clean it. I hope you find some articles that will at least get your friend to look thouroughly for hidden mold cuz it can destroy your lungs and health if you let it.