What Causes Frequent Black Outs?

My partner has been blacking out and collapsing for the past week now, ahe had a fall last night because she blacked out and was sent to hoppital and told she would have a scan thursday because she told them about the blacking out. Later that evening she again blacked out but this time wouldnt wake up she was rushed to hopptial and told she may have servere asma she been givirn inhalers and stuff when she gets out of breath and was told it would get better, but since she been given them she been getting them more regular but when she does there worse. We could be having a confersation and she would go and then wake up but this time she would be acting like a child or be angry or upset, but then go again and just finish off the previous conversation.