The effects of stress are far reaching. We mainly think of it as a mental state, but it can also have quite an effect on your physical self. The serious physical side effects of stress include high blood pressure, an increased heart rate and an overworked liver. Then there are nervous habits. These include scratching your skin, grinding your teeth, pulling at your hair, and the most common of all: nail biting. Although nail biting occurs most often in puberty, some people carry the nervous habit into adulthood. Although it's fairly harmless, it can increase your risk of infection and lead to sore or bleeding cuticles. If you're a nail biter, it's time to quell the habit by reading the following five tips.