High chances that these symptoms are caused by dust mite allergies and you are suffering without realizing it.
Recent studies show that house dust mites are the single great cause of asthmatic attack. This microscopic creature is found mainly in our homes where we spend 50% of our time. They live in carpets, fabric upholstered furniture, curtains and most of all in our beds. The higher level of exposure to this creature (its waste and dead body particles) the higher increase of allergy symptoms that lead to higher chances for asthma to happen.
About Dust Mites
55% of house dust consists of dust mites and their debris.They multiply in great numbers. Each month they lay up to 50 eggs. Tens of thousand of them sleep with you because your bed is their favourite place due to high humidity (by your sweat) and abundant food (your skin particles). They are very tough and normal laundering cannot kill them. They can resist the pull of even the most powerful vacuum cleaners.