Quad sets. 1  Sit with your leg straight and supported on the floor or a firm bed. (If you feel discomfort in the front or back of your knee, place a small towel roll under your knee.) 2  Tighten the muscles on top of your thigh by pressing the back of your knee flat down to the floor.
allergic reaction. allergic reaction in Medicine. allergic reaction n. A local or generalized reaction of an organism to internal or external contact with a specific allergen to which the organism has been previously sensitized. Examples from the Web for allergic reaction.
Severe Allergic Reaction Facts. Anaphylaxis is a severe allergic reaction that occurs rapidly and causes a life-threatening response involving the whole body. This reaction can lead to difficulty breathing and shock ultimately leading to death. For an anaphylactic reaction to occur, you must have been exposed in the past to the substance that causes the reaction, called the antigen. A bee sting, for example, may not cause an allergic reaction the first time.