The term sinus is usually used in reference to the cavities near the nose. If these cavities become inflamed or swollen, the condition is known as sinusitis. If this condition lasts for more than 12 weeks, it is categorized as chronic sinusitis. This leads to a buildup of mucus that can make breathing difficult. Home remedies may help relieve some of the symptoms associated with this condition but in most cases, medication is required.