Does your weight see-saw more than a five year-old at the playground? Well, you can relax. It's not unusual for a person's weight to fluctuate five pounds or more throughout the day. So here's why you may see higher numbers on the scale according to Dr. Melina Jampolis, author of The No-Time-To-Lose Diet: The first reason the scale may go up - you were following orders and drinking a lot of water. Downing 16 ounces of any liquid can cause an immediate gain of one pound. Another reason the number on the scale creeps up: You're constipated. If you haven't needed the room spray in the bathroom for a couple days, you're probably hanging on to a good two pounds extra. More reasons you're gaining weight: You've gone on vacation to Thailand, or somewhere else far away. Changes in air pressure can make you retain water on flights longer than four hours and that water retention can show up as an extra one to three pounds on the scale. Also, don't be concerned about your weight if you seem to have gained three pounds after a dinner of Chinese food. When you eat a salty meal like Kung Pao Chicken, your body retains water to dilute all that sodium in your system. Expect to weigh two to three pounds more after eating at Schezuan Palace - but don't worry. The added weight will go away after about 12 hours - once your body has digested the food. One last reason you may weigh more than normal: *Your hormones. Women in particular can retain enough water to inch the scale up about five pounds during certain times of the month. It's nothing to worry about and you'll be back to normal in a few days.