Sinusitis is an inflammation of the tissue lining the sinuses that often causes an infection and can result in mucus build-up and pain. It’s an incredibly common condition, with almost 40 million Americans suffering from sinusitis each year. Causes include respiratory infection, allergies, nasal polyps and a weakened immune system. Symptoms of sinusitis may include fever, weakness, fatigue, cough, congestion and mucus drainage in the back of the throat, called postnasal drip. About 90 percent of adults seen in the U.S. by a general practice physician for sinusitis are prescribed an antibiotic, even though antibiotics may not always be the best remedy, according to recent research and physician experts.194 Your body should be able to naturally overcome mild or moderate sinusitis without medication that can cause antibiotic resistance. Essential oils can greatly help with sinusitis symptoms, allowing your immune system to do its job.