Lies may come in all shapes and sizes and sometimes have a plethora of reasons behind them, from avoiding personal harm, wishing to avoid hurting someone or to protect them. Looking at facial expressions to determine whether a person is lying might just save you from being a victim of fraud. Or it could help you to know it's safe to trust your heart and get involved with an attractive stranger.
Look for micro-expressions. Micro-expressions are facial expressions that flash on a person's face for a fraction of a second and reveal the person's true emotion, underneath the lie. Some people may be naturally sensitive to them but almost anybody can train themselves to detect these micro-expressions.
Look for nose touching and mouth covering. People tend to touch the nose more when lying and a great deal less when telling the truth. This is perhaps due to a rush of adrenaline to the capillaries in the nose, causing the nose to itch. A lying person is more likely to cover his or her mouth with a hand or to place the hands near the mouth, almost as if to cover the lies coming forth. If the mouth appears tense and the lips are pursed, this can indicate distress.
Check for sweating. People tend to sweat more when they lie. Actually, measuring sweat is one of the ways that the polygraph test (the "lie detector" in all the movies) determines a lie. Yet again, taken on its own, this is not always a reliable indication of lying. Some people may sweat a lot more just because of nervousness, shyness or a condition that causes the person to sweat more than normal. It's one indicator to be read along with a group of signs, such as trembling, blushing and difficulty in swallowing.
Summary:
Typically, in a person who is lying, his or her micro-expression will be an emotion of distress, characterized by the eyebrows being drawn upwards towards the middle of the forehead, causing short lines to appear across the skin of the