Painful Flex

Hello, I am a sixteen year old female.  I am a pescetarian, an A student, and am very active.  I have been slightly sick recently with a small fever, post nasal drip, a cough, fatigue, and nausea.  Yesterday, I suffered from a migraine.  This morning around 4:30 am I was thrust awake by my left calf.  It had tightened up tighter than I've ever flexed it - felt as hard as plastic to the touch.  This flex that my calf was undergoing also HURT so bad I was screaming.  Extreme pain that made me feel as though my calf's muscle was tearing.  It was horrible, and the flex lasted almost two minutes, never stopping.  Massaging the area did nothing.  Once the flex loosened up and ended, the muscle was extremely sore, as though I had run 3 miles on that leg alone.  It is still sore now, 3 hours later, to the touch and when walking.  It was not a potassium cramp - I injest a minumum of 3 pints of milk every day.  Why did this happen?  Has this ever happened to anyone else?  What could this be sign of?  Please help.

[Dr Rajgopal]

Hi,
Muscle cramps generally result from overexertion and dehydration. When the fluid in the body is not enough, it leads to an electrolyte imbalance that causes your muscles to cramp up. Electrolytes such as sodium, magnesium, calcium and potassium help the cells to function normally. An imbalance occurs when we have too much or too little of one or more electrolytes in our system. The main electrolytes affecting muscle cramping are potassium, sodium and calcium. You may have had an electrolyte imbalance due to fever.
Cramps may also occur after prolonged inactivity, such as sitting too long in one place without moving the muscles. Sometimes you can even get a cramp when you're just lying in bed, though a definite cause is unknown. Muscle cramps can arise from spontaneous firing of special nerve groups followed by contraction of certain muscle fibers.
Cramps that are recurrent and localized to one muscle group may suggest nerve root disease. Please go for an MRI of the leg if cramps persist. Hope this helps you. Take care and regards!