Hyperthyroidism/gravis disease be the cause of extreme muscle pain?

[Worrisome59]

I’m a 23 year old female.  I’ve had hyperthyroid for 3-4 years now.  I received iodine/uptake treatment about 3 months ago.  My hyperthyroid symptoms have gotten better since the treatment; however, in the past month and a half I’ve noticed some muscle cramping.  Could this be related to the treatment I had or is this common for patients with hyperthyroidism/gravis disease? Soon before the cramping occurred, I worked on my arm for 2 days (5lbs in each arm…nothing strenuous…I’m 5’0 and weighed about 95lbs at the time).  Keep in mind I’m not an athletic person at all (Is this related to the cramping in anyway?)  I didn’t think much of it (or tried not to) until the cramping started to interfere with my sleep.  I would wake up, sometimes twitching before feeling my muscles tightening then finally my muscles would cramp up causing extreme discomfort and pain.  This would last anywhere between 2-30 minutes.  Sometimes the muscle cramp would only occur in one area, other times it would cramp up from one place to another.  This would happen repeatedly: it started off with the shoulder blades and triceps/biceps muscles cramping (with the mere movement to scratch my back) but soon followed (about 2 wks later) my abdominal muscles/side of my back, my muscles around my underarm, buttocks to the back of the thighs and the list continues to grow.  The cramping no longer occurs only at nighttime but in the morning as well, at work and sometimes when I’m driving (but not to the point I just can’t drive anymore).  Since the severe discomfort occurred, I started taking vitamins l

[CCF-Neuro-M.D.-JT]

There's a number of things that could possibly be going on.  Thyroid disease in itself, typically hypothyroidism, is well known to be associated with muscle cramping and weakness. Medications used to treat hyperthyroidism like PTU and methimazole have been reported by a group in Japan to cause severe cramping and muscle problems.  Finally, there is a muscles disease called stiffman or stiff-person syndrome that can be seen in women your age which presents with diffuse cramping.  It is also associated with thyroid disease and is thought to represent an immune response against a chemical in your body that helps to relax the muscle (very simplistically speaking). It's diagnosed with a blood test, clinical exam, and EMG.

As the cramping is getting worse, consider getting a neurological examination, bloodwork to look at muscle proteins like CK and aldolase, electrolytes, and possibly the anti-GAD antibody (for stiffman, depending on your doc's exam findings and clinical suspicion), and an EMG to help sort things out. Good luck.