Some acute TM patients may present symptoms of blurred vision and bulging eyes due to eye muscle degradation and inflammation, but documented cases are rare. Acute TM patients usually have very weak respiratory muscles and often severe respiratory failure occurs. Cause
TM is directly related to thyroxine toxicity. It is believed this disorder is a direct result of hyperthyroidism, specifically hyperthyroidism caused by Graves disease or a multinodular goiter. Both cause the thyroid gland to overproduce thyroxine. A multinodular goiter is a condition where the thyroid develops nodules. Overproduction of thyroxine is due to the enlargement of the thyroid gland. Graves disease is an autoimmune condition where the immune system chronically stimulates the TSH receptor in the thyroid and induces overproduction of the thyroxine hormone. Pathophysiology
Excess thyroxine is believed to bring about the onset of thyrotoxic myopathy and eventually cause the degradation of muscle tissue. Thyroxine is a hormone produced in the thyroid gland that regulates the growth metabolism of the nervous system and regulates basal metabolic rate of many cell types. Scientists agree thyroxine brings about the degradation of muscle fibers specifically at the motor end plates of neuromuscular junctions. There is debate as to whether thyroxine degrades the motor end plates from the muscular side, from the nervous system side, or a combination.To understand how high levels of thyroxine can be toxic and lead to thyrotoxic myopathy physiologically, consider basic neuromuscular junction function.
Brain
Glial scar

Heart
Myocardial fibrosis has mainly two forms:

Interstitial fibrosis, which has been described in congestive heart failure, hypertension, and normal aging. Replacement fibrosis, which indicates an older myocardial infarction. Other
Arterial stiffness
Arthrofibrosis (knee, shoulder, other joints)
Chronic kidney disease
Crohns disease (intestine)
Dupuytrens contracture (hands, fingers)
Keloid (skin)
Mediastinal fibrosis (soft tissue of the mediastinum)
Myelofibrosis (bone marrow)
Peyronies disease (penis)
Nephrogenic systemic fibrosis (skin)
Progressive massive fibrosis (lungs); a complication of coal workers pneumoconiosis
Retroperitoneal fibrosis (soft tissue of the retroperitoneum)
Scleroderma/systemic sclerosis (skin, lungs)
Some forms of adhesive capsulitis (shoulder)

References
External links
 Media related to Fibrosis at Wikimedia Commons