In chronic sinusitis, there is congestion and inflammation of the air sinuses in the skull. Air sinuses are air-filled spaces in the bones of the skull. They help to keep the skull light, maintain the humidity and temperature of the air entering the skull like air conditioners. They also maintain the pressure of the skull to keep brain floating and dampen the auditory vibrations reaching the skull. The air sinuses get infected and inflamed from infection in the surrounding areas of the brain. Most common cause for this is recurrent cold. Recurrent cold due to allergy or other causes produces congestion of the air spaces. Nasal obstruction due to polyps or a deviated septum also causes sinusitis. Infections of the teeth, throat, nose or ears can reach the air sinuses directly or via the blood stream and cause inflammation. Any trauma to the face or head can introduce germs which can reach the air sinuses and infect them. Among infections, viral infections most commonly cause cold and sinusitis. Bacteria like streptococcus pneumonia, Haemophilus influenza, et.c. are also responsible for this infection. In debilitated people, sinusitis can also be caused by fungal infections. Smokers are more prone to this condition. Chronic sinusitis, i.e., the one persisting for more than four weeks becomes a source of chronic headache. The pain is located over the site of infected sinus. It can be over the forehead in the middle or sides. The pain felt by an individual is throbbing. It is maximum in the morning but remains continuously present all the time. On looking down it is augmented. The affected person may have no other feature except this severe persistent headache. Hence it may be confused with migraine or tension headaches which occur due to mental tension. Some individuals experience loss of smell sensation due to chronic sinusitis. In case of bacterial infections there may be fever with rigors. If left untreated, there is risk of the infection reaching the coverings of brain or brain substance. This may manifest as convulsions, loss of consciousness and various neurological abnormalities. Diagnosis is based on clinical features. In individuals complaining of chronic headache and having history of recurrent cold like running of nose or sneezing, diagnosis of sinusitis becomes fairly easy. Imaging techniques like x-ray of the skull and computerised tomography help in confirming the diagnosis of chronic sinusitis. Treatment consists of taking a complete course of suitable antibiotic like amoxicillin or amoxicillin and clavulanic acid combination. In addition an anti-inflammatory drug is used to reduce the inflammation of the air sinuses. Steam inhalation done two to three times every day is very useful for patients with chronic sinusitis. It helps to liquify the secretions and drain them, thus relieving the congestion present in the air sinuses. Certain yoga exercises are also beneficial. Surgery is done in severe advanced cases of chronic sinusitis to clear the congestion of the air sinus. One should avoid exposure to allergy producing substances, thus allergic rhinitis and resultant sinusitis can be prevented. Any infection occurring anywhere in the ear, nose or mouth should be promptly treated to avoid chronic sinusitis. The writer is a specialist internal medicine-Ruhengeri District Hospital