If a child has frequent headaches, unilateral or bilateral nasal congestion, more mucous-purulent nasal discharge, and a lack of concentration and disinterest in food, the writer should be alert at this time. It is important to know that this is not a child suffering from a cold that is not well, but a sinusitis. What is sinusitis all about? It starts with the sinuses. Sinus is a hole or cavity, and sinus is a symmetrical cavity around the bones around the nasal cavity, there are four pairs. The largest pair of sinuses is the cavity in the maxilla called the maxillary sinus, located in the forehead in the middle of the arch of the eyebrow called the frontal sinus, the top of the nasal cavity like a sieve cavity called the sieve sinus, and a pair of long at the base of the skull whose shape is very much like a butterfly called the butterfly sinus. Each pair of sinuses has an opening into the nasal cavity called sinus opening, tiny sinus opening is very easy to become more narrow or blocked due to nasal foreign body or inflammation, thus affecting the ventilation and drainage of the sinuses. The sinuses are also lined with a layer of mucous membrane and are continuous with the mucous membrane of the nasal cavity. When a child has a cold, the mucous membrane of the nasal cavity becomes inflamed and if not treated promptly, the inflammation in the nasal cavity spreads and invades the sinuses causing acute sinusitis. Colds are the most important cause of sinusitis in children. The presence of a nasal foreign body, which hinders the drainage of secretions in the sinuses, can also cause sinusitis. If a child has tooth decay and it is not treated in time, the root of the tooth becomes inflamed, which can trigger inflammation of the maxillary sinus near the root of the tooth. Thus, it seems that sinusitis is really a common disease in children. Sinusitis can be divided into two categories: acute and chronic. The main manifestation of acute sinusitis is that the child should gradually heal after 1 week of suffering from a cold, but then the nasal mucus increases instead, and is mostly pus, and even a bit smelly, still fever, headache, nasal congestion, but also do not like to eat. Acute sinusitis is usually cured gradually as long as the treatment is timely. The treatment is usually intramuscular injection of penicillin or other antibacterial agents, nasal drops such as ephedrine to promote drainage of nasal secretions, and sometimes the doctor will take certain measures such as physical therapy, puncture rinses, and replacement aspirations. The important thing is that timely treatment can prevent the transformation to chronic sinusitis. Chronic sinusitis is most often caused by delayed treatment of acute sinusitis mistaken for a cold. Yellow nasal discharge, nasal congestion, frequent headaches, mental discomfort and poor memory are typical manifestations of chronic sinusitis. Chronic sinusitis is more troublesome to treat and often relapses due to colds after it is cured. But after all, children’s sinusitis because the lesion is short, the lesion tissue is easier to recover, as long as adhere to the correct treatment, or can be cured.