Now your friends may all know how funny you are but a nervous man will laugh at everything you have to say... whether it is funny or not. Unexplained laughter is a sure sign of nervousness. A nervous man will laugh sometimes when he doesn't realize he's doing so. He does this subconsciously to let you know he finds you interesting and that he enjoys being around you.
Lack of Eye Contact
A nervous man is usually one who doesn't have a lot of confidence. When you are around the man, if you make eye contact with him and he looks away quickly, this is a sign that he is nervous or shy around you. Not being able to hold eye contact for a length of time is a sure sign he is not very confident in your presence and could be suffering from nervousness.
You notice little beads of sweat forming on his forehead... and it's 40 degrees F outside. Or maybe he goes to open the door for you and you notice that the door handle is wet from his sweaty palms. Perspiration is a sign that his heart is beating faster than normal, which is also a symptom of nervousness. But sorry, if you are hanging out playing a game of tennis, his sweat is due to physical activity.
Talks About Himself
You may think that the guy is a bit chattier than normal. He seems uncomfortable with silence and can't stop talking about himself. Most likely he is nervous that you won't like him and is desperate to impress you with his intellectual prowess or his many successes. He may also be uncomfortable with silence, and to distract himself from nervousness, he decides to fill the void with his own voice.