Drug Reaction to various drugs is not a rare thing as most of the drugs come with various side effects. The reactions caused by various drugs are generally of two types – mild reaction by drugs and adverse reaction of drugs. Mild drug reaction symptoms include stomach ache or drowsiness. Adverse drug reaction symptoms are very notable and one needs to be able to identify them. Some of the reactions can be allergic, and in times when the immune system comes across any substance which evokes an adverse drug reaction when there is a lack of antibodies to tackle the particular reaction or infection. The often seen drug reaction symptoms include nausea, dizziness, loss of consciousness, drop in blood pressure, tightening of the airways and body rash. Severe drug reactions can lead to weakened bones and frequent headaches. If you experience any such symptoms you should not delay a visit to your General Physician and discuss about the symptoms you experience. After examining you, your General Physician would observe the severity of your condition. In case of a mild reaction he would recommend oral medications or in a case of adverse reactions your doctor may put you through a course of injections.