Researchers at the Institute for Lung Health at the University of Leicester and Glenfield Hospital, examined the impact on asthmatics of a common environmental mould, Aspergillus fumigatus, usually found in soil and compost heaps - their report has been published A report published in the December 2010 issue of the American Journal of Respiratory and Critical Care Medicine.
Professor Andy Wardlaw from the University of Leicester said: “Asthma is a very common condition where the breathing tubes (bronchi) can go into spasm making it difficult to breathe. Around a fifth of adults with severe asthma, which they have had for a long time, get permanent (fixed) narrowing of their bronchi. It is known that A. fumigatus can grow in the lungs of some people with asthma and mould allergy, which can cause severe lung damage.
“This problem is thought to only affect a very small number of people with asthma; however, about half of people with severe asthma have evidence of allergy to moulds like A. fumigatus.”

 http://www.horticulture-news.com/common-garden-mould-found-growing-in-asthmati

Fungus and mildew are seen as triggers for asthma

. Ireland already has the fourth highest incidence of asthma in the world and allergies are rising fast. Alarmingly things may be getting worse: recently the World Health Organisation has found that as many as third of Irish children now have asthma. 
Condensation is the formation of liquid water from air when the temperature of the air reaches its dew point.  This is most lightly to occur during winter months when the walls are cold and the internal air is warm especially in locations where the relative humidity of the internal air is high   Bathrooms and kitchens are common locations where this occurs, but also bedrooms in the early hours of the morning

Asthma and Mould

Moulds are types of fungi that grow indoors and outdoors in damp, dark places, and usually have a musty smell. there are different species of mould. Moulds release tiny seeds called spores into the air, which can trigger asthma symptoms in some people. Mould spores are found in any damp place - from piles of autumn leaves and woody areas to bathrooms, kitchens and even piles of damp clothes. The spores that moulds give off may cause allergic reactions throughout the year.

Black mold in the bedroom

We too have serious black mold in the bedroom. It can be caused by warm air touching the cold walls.
Ours has become worse since we got better heating in the house!
From what i have read, the mold likes paper. This seems to be so in our bedroom as the Mold is on the wallpapered wall and the dry-lined wall! The walls that have no paper that are just painted walls, have no mold!
We now have a dehumidifier and I have been told there is something to put into paint that stops the growth of the mold so I am going to research into that this week.
It has been such high humidity this year with all the rain that it is a real problem.
I think moving to somewhere warmer and drier would swing it for me!! :-)