Sleep disturbance is one of the symptoms of jet lag, the infamous physiological condition that occurs after long-haul flights, usually when traveling east. Jet lag is caused by the de-synchronization of our body clock (or our circadian rhythm, to use the medical term). Symptoms may also include reduced concentration, irritability, headaches, problems with digestion, and fatigue. However, it is not always jet lag to blame when our sleep gets disrupted. In fact, a lot of people may find it difficult to fall asleep, have frequent awakenings and difficulty to get back to sleep, wake up early, have a restless sleep, or even sleep too much. There are many potential reasons…