What is the primary system affected by chronic sinusitis?

Chronic sinusitis primarily affects the respiratory system, as it involves inflammation and swelling of the sinuses, which are air-filled spaces located within the bones surrounding the nasal cavity. This condition leads to an obstruction of the sinus drainage pathways, causing symptoms such as congestion, facial pain, nasal discharge, and difficulty breathing through the nose.

The respiratory system is directly involved because the sinuses are interconnected with the nasal passages and directly impact airflow and mucus production. Consequently, any dysfunction in the sinuses, such as that caused by chronic sinusitis, can lead to significant respiratory symptoms that require attention and management.

Other systems listed are not the primary focus of chronic sinusitis. The endocrine system, cardiovascular system, and digestive system do not have the same direct and immediate involvement with the pathophysiology of sinusitis as the respiratory system does.