Lightheadedness - anxiety or something else?

[JS1902]

I've been having these occasional and random spells of lightheadedness for a while now, only happens when I am at work and talking to someone. For example, I go for a walk at lunch time, and sometimes when speaking to the reception ladies on the way in I feel as if I am going to pass out. Sometimes I have to cut the conversation short and go to my desk to steady myself, sometimes if I persevere the feeling fades. On some days it doesn't happen and I'm fine. It seems to happen more when I've had a crappy nights sleep and have tension in my neck muscles if that makes sense. I've had a full blood count recently for something else and came back fine. I play 5 a side football and tennis and feel completely fine, so wondering what this could be.

[Piersman2]

Is the receptionist hot?