Chronic sinusitis is a condition in which the sinuses become inflamed and swollen for a prolonged period of time. This can cause a buildup of mucus, which can lead to congestion, difficulty breathing, and pain. Treatment for chronic sinusitis typically involves a combination of medication and home care. Medication may include antibiotics, antihistamines, and decongestants. Home care measures may include using a humidifier, drinking plenty of fluids, and avoiding irritants such as smoke and dust. In some cases, surgery may be necessary to open the blocked sinuses and allow drainage.