Depends. Sinusitis is sometimes an unclear diagnosis, so first i would have to know more about your symptoms. If you have a cold-like symptoms such as runny nose, fever, headache, postnasal drip that have persisted for more than 7 to 10 days, you may have sinusitis. Many get better without treatment, but if symptoms are bad, antibiotics may help relieve symptoms faster.
Increase drainage. Sinus health is all about drainage. In addition to killing off a bacterial infection with antibiotics, you can use topical decongestants like afrin (for no more than a week), oral decongestants like sudafed (if tolerated), and sinus rinses with saline to wash away the thick mucus that is plugging the drain openings. Nasal steroid sprays also help by reducing the inflammation in the sinuses.