How to Explain some unexplained weight loss

Unexplained weight loss may be generated from some disease and most frequent is thyroid disorders and also undiagnosed celiac disease. There is a list with potential causes that can explain some of unexplained weight loss :

Addison's disease
  Cancer
  celiac disease
  COPD
  Crohn's disease
  dementia
  Depression (major depression)
  diabetes
  heart failure
  HIV / AIDS
  hypercalcemia
  Hyperthyroidism (overactive thyroid)
  Hypothyroidism (underactive thyroid)
  Parkinson's disease
  peptic ulcer
  tuberculosis
  ulcerative colitis