Created: Monday, November 12, 2007

Causes of Myositis Muscle Diseases Myopathy.

Myopathy is a condition in which the muscles become weak. Myopaty

The acquired myopathy result from other disorders like inflammation.
Secondary metabolic and endocrine myopathies:
Thyroid disease:
Myxoedema can present with myopathyoverweight, slow (under active thyroid)
Hyperthyroidism.eyes bulge out, hot feeling, thin(over active thyroid)
Parathyroid dysfunction:
Hypoparathyroidism-causes tetany which is repeated spasms of fingers
Hyperparathyroidism-causes proximal myopathy. (weakness in thighs & shoulders)
Pituitary dysfunction (for example Addison disease)- myopathy through either adrenal dysfunction or secondary thyroid dysfunction.

Cushing disease
Exogenous steroids- especially high doses (over 25mg per day). steroid myopathy
Hypokalaemia (low potassium) and hyperkalaemia can cause muscle weakness and myotonia (stiffness)
May be caused by varieties of acute periodic paralysis (genetic)
Secondary to acute gastrointestinal loss of potassium
Secondary to endocrine disease
Renal disease kidney failure cause
Excessive liquorice ingestion.
Diabtetes mellitus.

Drug induced myopathy:
Statins due to lowering cholesterol,Steroids ,Cocaine ,Colchicine. ,
Infectious causes:
Trichinosis ,Toxoplasmosis ,Human immunodeficiency virus (HIV)
Coxsackie viruses ,Influenza ,Lyme disease.
Polymyalgia rheumatica:
Proximal myopathy with associated muscle tenderness.


These are all relatively uncommon diseases. DMD has the highest prevalence of the myopathies.Presentationcontinue to Myopathy PRESENTATION