Sinusitis is cause by inflammation of the mucous membranes in the sinuses, the air-filled spaces in the bones of the face. Sinus symptoms are a blocked-up nose, a nasal tone in the speech, and sometimes a headache over one or both eyes, usually worse in the mornings, when lying down or bending forwards. Normally mucus is channeled through the tiny air ducts to the nose, but during colds the ducts can become congested and when the mucus builds up, the sinuses become inflamed. Hay fever can also cause sinusitis, and allergy to dust or tobacco smoke can result in chronic cases. There can also be a greenish-yellow or bloody discharge from the nose.

Chinese Medicine sees the condition as mainly connected with a lung Qi deficiency and with damp heat. A Chinese Medicine practitioner will prescribe peppermint, honeysuckle, fritillary bulb, tangerine peel and xanthium fruit are all helpful.