Can long term cat ammonia seep through walls ?

Ever since I moved into a flat I had nothing but illness. One headache after the other nearly every other day. Stuffy nose and catarrh always hanging down my throat. Itchy eyes etc. My flat was like a vacum in the winter and I didnt open the windows much because it was cold. However Ive discovered the man in the flat below has 3 cats and cat trays around his house that he doesnt clean too often. Ive read somewhere that cat ammonia odour can seep into walls and floors. My flat is like a chalet the walls and floors are thin. Anyhow just recently Ive been able to open the windows because of the nice weather and my health has improved. Im wondering if Im suffering the effects of this mans cats. Hes been here 10 years and has had 10 years of cat ammonia floating around his flat. Has anyone else experienced anything like this? It was only when a friend of mine made the connection that Im wondering if cat ammonia can rise into the air and walls of a thinly built flat?

I thought I was going mad or had something seriously wrong with me becoming ill time after time and getting these headaches every other day. Ive not had a headache since my windows have been opened. Ive complained to the housing association Im living in but I doubt they will do anything about this.