Hives are red, somewhat raises patches on your skin and are normally shaped erratically. They could be very small and spotty in size or they could spread over areas as large as CD disks. Hives could come and go within an hour or they could continue for weeks. Ordinary hives are those which appear abruptly, at times for no obvious reason or perhaps because you ate food which caused an allergic reaction.Physical hives are the result of a specific spur to the skin such as sunlight, extreme temperatures or pressure. If they last longer than 6 weeks then doctors call them as chronic hives. Managing your stress levels is also important as each and every day you are under stress. At times you are aware of the stress which is affecting you but you can?t do much about it. Stress is one of the reasons for hives causes. Chemicals known as neurotransmitters in your cells warn other cells that change is occurring and your body gets ready for a fight or flight response. One of these neurotransmitters corresponds with emotional changes and affects the major organs and the smooth muscle cells.Your skin is the body?s largest organ and the signals sent by neurotransmitters cause red blood cells to produce clear liquid plasmacytes which have nowhere to go except in pockets under the skin. These are known as the itchy, red hives.Remember, stress causes hives in more than one way and it?s vital that you keep yourself away from it.