It is an infection of upper respiratory tract which involves nose, throat, tonsils, sinuses, larynx, and pharynx. It includes respiratory illness like common cold, cough, sore throat, allergic rhinitis, nasal obstruction, otitis media, sinusitis, laryngitis, pharyngitis.

• Common cold is caused when the viruses interfere with breathing process. The nasal passages and upper respiratory tract becomes swollen, congested and inflammation in case of immune system fails.

• Cough is a reflex action caused by spasmodic contraction of diaphragm which helps to expel infected mucus or phlegm from the airways of the lungs.

• Allergic rhinitis is also known as hay fever. It causes inflammation of the nasal passages caused by allergic reaction to airborne substances. Two types of allergic rhinitis are seasonal rhinitis and perennial rhinitis. Seasonal AR occurs in the spring, summer and early fall when the plant pollens are at their highest levels in air. Perennial AR occurs all over the year.

• Rhino sinusitis is generally known as sinusitis. Sinusitis is of two types’ acute sinusitis and chronic sinusitis. Symptoms of sinusitis include headaches, fever, cough, sore throat, a poor sense of smell, facial pain, and thick nasal mucus. If the symptoms last fewer than 4 weeks it is called as acute sinusitis and if the symptom lasts for more than 12 weeks it is chronic sinusitis.

• Tonsillitis is characterized by inflammation to tonsils. The disease is confirmed by a rapid strep test and throat swab. The infection spreads between people through the air. Symptoms of the disease may include trouble in swallowing, enlargement of tonsils.

• Pharyngitis forms inflammation on the back of the throat that is pharynx. Fever, headache, sore throat, runny nose, cough, difficulty in swallowing, inflammation in lymph nodes and a hoarse voice are the common symptoms of sinusitis which usually lasts for 3–5 days.

• Laryngitis causes inflammation to the larynx. Pain in the front of the neck and other symptoms are similar to pharyngitis. Laryngitis is categorized as acute and chronic. If the symptom lasts less than three weeks it is acute and if the symptoms last more than three weeks it is chronic. Chronic cases may occur due to smoking, allergies, acid reflux, tuberculosis, sarcoidosisand rheumatoid arthritis.