1. Almost all causes of sinusitis are viruses (Human Respiratory Syncytial Virus, Parainflueza Virus, Metapneumo Virus), bacteria (Streptococcus pneumoniae, Haemophilus influenzae) and fungi.
2. Sinusitis occurs when the immune system is reduced due to fungal attack.
3. Allergies can cause this disease.
4. If the nasal passages are narrowed or blocked and if there is a polyp or lump inside the nose.
5. A tooth infection or a sinus infection due to tooth extraction.
6. If the dirty water enters the nasal sinuses if the dirty water is splashed.
7. If the nasal bones are bent or cracked.
8. This disease occurs when the tonsils behind the nose are enlarged.
9. Sinusitis occurs when the airways are narrowed as a result of inflammation of the nasal mucosa or when the sinus cavity is blocked by an abnormality of the septum.
10. Cystic fibrosis is caused by the gene.
11. Chronic sinusitis occurs when the Eustachian tube is abnormal and obstructed.
12. Sinusitis is caused by malnutrition, cold, pollution and damp environment.

Sinusitis can be divided into two categories on the basis of persistence. namely-
1. Acute sinusitis: If the duration of inflammation of the disease is 4-8 weeks, it is called acute sinusitis.
2. Chronic sinusitis: If the duration of inflammation of the disease is more than 2-3 months, it is called chronic sinusitis.

The face has four pairs of air-filled nasal cavities or sinuses. These are-
1. Maxillary sinus: A pair of maxillary sinuses are located in the cheek in the maxillary region. Its inflammation causes pain in the cheeks, teeth and head.
2. Ethmoid sinus: A pair of ethmoid sinuses is located between the two eyes. Its inflammation causes pain in front of the eyes, behind and in the head.
3. Sphenoid sinus: A pair of sphenoid sinuses are located behind both eyes. Its inflammation causes pain behind the eyes and on top of the head.
4. Frontal sinus: A pair of frontal sinuses are located above the eyes. Its inflammation causes pain above the eyes and on top of the head.

Sinusitis is the inflammation that occurs in the mucous membrane of the paranasal sinuses or sinuses due to viral, bacterial and fungal attacks or allergies. In medical science, the infection of the sinuses of the upper respiratory tract, i.e. the nose, ears and throat, is called sinusitis. Sinusitis is diagnosed by peripheral nerve stimulation (PNS) X-ray.

Lower respiratory tract infection is an infection of the trachea and lungs. These include flu (infection of the respiratory tract), bronchitis (infection of the respiratory tract), pneumonia (infection of the lungs), tuberculosis or tuberculosis (chronic bacterial infection of the lungs).

An upper respiratory tract infection is an infection of the nose, ears, throat and sinuses. Tonsillitis (infection of the tonsils), sinusitis (infection of the sinuses), laryngitis (infection of the larynx), otitis media (infection of the ear) etc. are the main ones. Symptoms of these infections include sneezing, coughing, sore throat, headache, runny nose, etc.

Any type of infection in the throat, sinuses, trachea and lungs is called Respiratory Tract Infection (RTI). Cold is the biggest RTI problem. Doctors have identified RTI in two ways. These are-
1. Upper respiratory tract infection: An upper respiratory tract infection is an infection of the nose, ears, throat and sinuses. Tonsillitis (infection of the tonsils), sinusitis (infection of the sinuses), laryngitis (infection of the larynx), otitis media (infection of the ear) etc. are the main ones. Symptoms of these infections include sneezing, coughing, sore throat, headache, runny nose, etc.
2. Lower respiratory tract infection: Lower respiratory tract infection is an infection of the trachea and lungs. These include flu (infection of the respiratory tract), bronchitis (infection of the respiratory tract), pneumonia (infection of the lungs), tuberculosis or tuberculosis (chronic bacterial infection of the lungs).

Myoglobin is an iron chelator. It looks like hemoglobin. While hemoglobin binds to 4 oxygen molecules, myoglobin can bind to only 1 oxygen molecule. It is found in skeletal muscle. Myoglobin is highest in muscles that work continuously.

Carbon dioxide reacts with haemoglobin in body cells to form carbaminohemoglobin compound. Carbaminohemoglobin comes from the compound body cells to the walls of the alveoli. The compound breaks down in the walls of the alveoli and turns into carbon dioxide and haemoglobin. Carbon dioxide is then released from the body.
CO2 + HbNH2 → HbNHCOOH
Haemoglobin acts as the sole carrier for transporting oxygen and carbon dioxide in the human body. That is, oxygen and carbon dioxide transport is not possible without red blood cells.

Oxygen combines with hemoglobin in red blood cells to form oxyhemoglobin. Oxyhemoglobin reaches different parts of the body. Oxyhemoglobin breaks down in body cells and oxygen and hemoglobin are released. As a result, body cells get the necessary oxygen.
Hb4 + 4O2 → 4Hbo2
Actually hemoglobin reacts with 4 oxygen molecules to form Hb4o8.
Hb4 + O2 → Hb4o2
Hb4o2 + O2 → Hb4o4
Hb4o4 + O2 → Hb4o6
Hb4o6 + O2 → Hb4o8
This reaction is extremely fast and takes less than 0.01 second. Temperature, pH and red blood cell diphosphoglycerate affect this reaction.