Immunization Twinrix administered at Health Clinic on January 28, 2011 at approximately 9:30 AM.  This was part of a pre-college physical examination. I also received the meningococcal meningitis immunization. The first sign of an adverse reaction was at approximately 6:30 PM that evening when I was standing in a restaurant waiting to order food.  I suddenly became extremely dizzy and had to sit down.  This dizziness lasted about 5 minutes.  Over the next several days, the dizziness continued with progressively worsening symptoms (ie:  feeling lightheaded and body feeling numb/fuzzy/weak).  On Monday, February 7, 2011 at 2:55pm, the dizziness/lightheadedness was so extreme that my vision was blurry and my whole body felt numb/week.  All I was doing was sitting at my desk in school.  Class ended 5 minutes later and I went immediately home and my dad took me to the Health Clinic  this was approximately 4:15pm.  I initially saw PA and she took my blood pressure and pulse (repeatedly) and drew blood and tested my urine.  They ran an EKG and said that was normal.  They did some neurological tests  touching my finger to my nose, crossing my legs, walking a straight line, etc.  My blood showed my "potassium was a little low".  Otherwise, everything else was normal and they couldn't figure out what was wrong.  We did mention to them the fact that I had received the Twinrix immunization and they said they couldn't rule that out as a reason for my symptoms. Dr. was called in to consult multiple times.  Neither could figure out what was going on.  The clinic was closed and they were still debating about what to do.  They suggested admitting me to the hospital but my parents wanted to discuss our options so I went home.  This was approximately 6:30pm. I went home and my Dad then brought me to  Emergency Room.  They checked my blood pressure, pulse (repeatedly) and another EKG.  They started an IV for fluids because they said I was "severely dehydrated".  They drew more blood and tested that for everything they needed.  They did a chest xray after the IV was inserted and the report was that everything was normal.   My heart rate did decrease some with fluid so the IV was finished and I was released.  I did feel slightly better, but the dizziness was still present.  Diagnosis was "severe dehydration" with notes to follow up with my doctor if my symptoms didn't improve. On Tuesday, February 8th, I stayed home from school.  I was still feeling slightly dizzy but it seemed milder than it had before. On Wednesday, February 9th, I went back to school and felt slightly dizzy but in Band, my 2nd hour class (at about 9:40am), after playing my bass clarinet for a little while, I started feeling VERY dizzy.  I drank a lot of water trying to make it stop, but that didn't help so I went to the teacher and he had someone  accompany me to the nurse.  She took my blood pressure and pulse, but which were slightly elevated.  My temperature was normal.  She called my mom who came and got me. I got an appointment with my pediatrician for 11:45am.  He took my blood pressure, pulse and he did a short exam of my ears, throat, glands, etc.  He suggested it could be "POTS" (Postural orthostatic tachycardia syndrome) and said that it sometimes occurs after an illness or immunization.  I asked if the Twinrix could be the reason and he said he couldn't rule that out.  He said he would consult with a cardiologist and get back to me. I went home and Dr. called and spoke with my mom.  He asked that she take my resting pulse rate and then take it again, with me standing, at 5, 10 and 15 minutes.  My heart rate increased by more than 30 beats upon standing, so Dr. relayed this information to the cardiologist.  He has scheduled a Holter monitor to be applied on Wednesday, February 16, 2011. On Thursday and Friday, February 10th and 11th, I stayed home from school.  I felt dizzy/lightheaded frequently.  It seems to be worse if I am sitting or standing  I frequently have dizzy feelings when sitting at the table eating, for example.  I am most comfortable on the sofa or in bed.  I continue to be unable to participate in normal activities, having to skip my ice skating lesson on Saturday, February 12th. Dr. has advised that I may resume normal activities as tolerated, but with continued dizziness, I am not tolerating normal activities at all.