The sinuses are hollow cavities in the skull that are present around the forehead, cheeks, and nose. A thin layer of mucus lines the sinuses to keep them moist and trap bacteria. If the body stops producing as much mucus, the sinuses can become dry, leading to a feeling of uncomfortable dryness in the nose and airways. Depending on the cause, people with dry sinuses may also experience nosebleeds or sinus infections. If someone has dry sinuses that do not improve with home treatment, they should see a doctor if possible. Dry sinuses are sometimes due to an underlying condition, which may require medication. Over time, dry sinuses can lead to a buildup of thick mucus. This buildup prevents the sinuses from clearing away potentially harmful bacteria, which can cause a sinus infection. Staying hydrated, inhaling steam, and using a humidifier may relieve irritation. Persistently dry sinuses may indicate an underlying condition, or they may occur as a side effect of a medication. A doctor will be able to diagnose the root cause and recommend medication changes if necessary.