An underestimated comorbidity of COPD: Thyroid dysfunction.

Chronic obstructive pulmonary disease (COPD) has many systemic effects influencing morbidity and mortality of the disease. Thyroid diseases which are more common in COPD patients than who do not have COPD are underestimated despite important clinical consequences. Similar to general population, thyroid dysfunctions are more common in females than males among COPD patients. Both hypothyroidism and hyperthyroidism may be associated to COPD. As well as systemic inflammation hypoxia, age, glucocorticoid use and smoking are some of the effective factors on developing thyroid dysfunction in COPD patients. In this article thyroid dysfunctions that are underrecognized comorbidities of COPD patients, their mechanisms of action and clinical outcomes were reviewed.