What Causes Dizziness, Blurry Vision And Sweating?

Hi, yesterday I sort of fainted but didn't collapse. All of a sudden I felt nauseus and dizzy and lightheaded, then I lost my vision and hearing and was all sweaty and felt awful. It was like faiting, but I didn't actually faint. Is this another way of fainting or what is it? SHould I be concerned? I had been feeling fine. I had eaten and had water, and wasn't too hot or anything. No idea what caused it.
Age 26. Female. Healthy. 10and half stone