E21 | 
		  | 
		Hyperparathyroidism and other disorders of parathyroid gland  | 
	
	
		 |  | 
		
	
		| Excludes1 | 
		adult osteomalacia (M83.-) ectopic hyperparathyroidism (E34.2) hungry bone syndrome (E83.81) infantile and juvenile osteomalacia (E55.0)
  | 
	 
	
		| Excludes2 | 
		familial hypocalciuric hypercalcemia (E83.52)
  | 
	 
 
 | 
	
 |  | 
	
		 E21.0 | 
		  | 
		Primary hyperparathyroidism | 
	 
	
		 |  | 
		
| Hyperplasia of parathyroid |  | Osteitis fibrosa cystica generalisata [von Recklinghausen's disease of bone] |   
 | 
	   | 
 |  | 
	
		 E21.1 | 
		  | 
		Secondary hyperparathyroidism, not elsewhere classified | 
	 
	
		 |  | 
		
	
		| Excludes1 | 
		secondary hyperparathyroidism of renal origin (N25.81)
  | 
	 
 
 | 
	   | 
 |  | 
	
		 E21.2 | 
		  | 
		Other hyperparathyroidism | 
	 
	
		 |  | 
		
| Tertiary hyperparathyroidism |  	
		| Excludes1 | 
		familial hypocalciuric hypercalcemia (E83.52)
  | 
	 
 
 | 
	   | 
 |  | 
	
		 E21.3 | 
		 | 
		Hyperparathyroidism, unspecified | 
	 
  | 
 |  | 
	
		 E21.4 | 
		 | 
		Other specified disorders of parathyroid gland | 
	 
  | 
 |  | 
	
		 E21.5 | 
		 | 
		Disorder of parathyroid gland, unspecified | 
	 
  |