Pharyngitis is a type of inflammation, most commonly caused by an upper respiratory tract infection. It may be classified as acute or chronic. Acute pharyngitis may be catarrhal, purulent or ulcerative, depending on the causative agent and the immune capacity of the affected individual. Chronic pharyngitis may be catarrhal, hypertrophic or atrophic.

Tonsillitis is a sub type of pharyngitis. If the inflammation includes both the tonsils and other parts of the throat, it may be called pharyngotonsillitis. Another sub classification is nasopharyngitis (the common cold).

Common signs and symptoms include:

- sore throat

- red, swollen tonsils

- pain when swallowing

- high temperature (fever)

- headache

- tiredness

- chills

- a general sense of feeling unwell (malaise)

- white pus-filled spots on the tonsils

- swollen lymph nodes (glands) in the neck

- pain in the ears or neck

- weight loss

- difficulty ingesting and swallowing meal/liquid intake

- difficulty sleeping

Less common symptoms include:

- nausea

- fatigue

- stomach ache

- vomiting

- furry tongue

- bad breath (halitosis)

- voice changes

- difficulty opening the mouth (trismus)

- loss of appetite

- Anxiety/fear of choking

In cases of acute tonsillitis, the surface of the tonsil may be bright red and with visible white areas or streaks of pus.

Tonsilloliths occur in up to 10% of the population frequently due to episodes of tonsillitis.

Pharyngitis is inflammation of the back of the throat, known as the pharynx. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, a hoarse voice. Symptoms usually last three to five days. Complications can include sinusitis and acute otitis media. Pharyngitis is typically a type of respiratory tract infection.

Most cases are caused by a viral infection. Strep throat, a bacterial infection, is the cause in about 25% of children and 10% of adults. Uncommon causes include other bacteria such as gonorrhea, fungus, irritants such as smoke, allergies, and gastroesophageal reflux disease. Specific testing is not recommended in people who have clear symptoms of a viral infection such as a cold. Otherwise a rapid antigen detection test (RAPD) or throat swab is recommended. Other conditions that can produce similar symptoms include epiglottitis, thyroiditis, retropharyngeal abscess, and occasionally heart disease.

NSAIDs, such as ibuprofen, can be used to help with the pain. Topical lidocaine may also help. Strep throat is typically treated with antibiotics, such as either penicillin or amoxicillin. It is unclear if steroids are useful in acute pharyngitis, other than possibly in severe cases.

About 7.5% of people have a sore throat in any three-month period. Two to three episodes in a year is not uncommon. This resulted in 15 million physician visits in the United States in 2007. Pharyngitis is the most common cause of a sore throat. The word comes from the Greek word "pharynx" meaning "throat" and the suffix "-itis" meaning "inflammation".

The typical signs and symptoms of streptococcal pharyngitis are a sore throat, fever of greater than , tonsillar exudates (pus on the tonsils), and large cervical lymph nodes.

Other symptoms include: headache, nausea and vomiting, abdominal pain, muscle pain, or a scarlatiniform rash or palatal petechiae, the latter being an uncommon but highly specific finding.

Symptoms typically begin one to three days after exposure and last seven to ten days.

Strep throat is unlikely when any of the symptoms of red eyes, hoarseness, runny nose, or mouth ulcers are present. It is also unlikely when there is no fever.

Tonsillitis is inflammation of the tonsils, typically of rapid onset. It is a type of pharyngitis. Symptoms may include sore throat, fever, enlargement of the tonsils, trouble swallowing, and large lymph nodes around the neck. Complications include peritonsillar abscess.

Tonsillitis is most commonly caused by a viral infection, with about 5% to 40% of cases caused by a bacterial infection. When caused by the bacterium group A streptococcus, it is referred to as strep throat. Rarely bacteria such as "Neisseria gonorrhoeae", "Corynebacterium diphtheriae", or "Haemophilus influenzae" may be the cause. Typically the infection is spread between people through the air. A scoring system, such as the Centor score, may help separate possible causes. Confirmation may be by a throat swab or rapid strep test.

Treatment efforts involve improving symptoms and decreasing complications. Paracetamol (acetaminophen) and ibuprofen may be used to help with pain. If strep throat is present the antibiotic penicillin by mouth is generally recommended. In those who are allergic to penicillin, cephalosporins or macrolides may be used. In children with frequent episodes of tonsillitis, tonsillectomy modestly decreases the risk of future episodes.

About 7.5% of people have a sore throat in any three-month period and 2% of people visit a doctor for tonsillitis each year. It is most common in school aged children and typically occurs in the fall and winter months. The majority of people recover with or without medication. In 40% of people, symptoms resolve within three days, and in 80% symptoms resolve within one week, regardless of if streptococcus is present. Antibiotics decrease symptom duration by approximately 16 hours.

In uncomplicated colds, cough and nasal discharge may persist for 14 days or more even after other symptoms have resolved.

Acute upper respiratory tract infections include rhinitis, pharyngitis/tonsillitis and laryngitis often referred to as a common cold, and their complications: sinusitis, ear infection and sometimes bronchitis (though bronchi are generally classified as part of the lower respiratory tract.) Symptoms of URTIs commonly include cough, sore throat, runny nose, nasal congestion, headache, low-grade fever, facial pressure and sneezing.

Symptoms of rhinovirus in children usually begin 1–3 days after exposure. The illness usually lasts 7–10 more days.

Color or consistency changes in mucous discharge to yellow, thick, or green are the natural course of viral upper respiratory tract infection and not an indication for antibiotics.

Group A beta hemolytic streptococcal pharyngitis/tonsillitis (strep throat) typically presents with a sudden onset of sore throat, pain with swallowing and fever. Strep throat does not usually cause runny nose, voice changes, or cough.

Pain and pressure of the ear caused by a middle ear infection (otitis media) and the reddening of the eye caused by viral conjunctivitis are often associated with upper respiratory infections.

A URI may be classified by the area inflamed.

Rhinitis affects the nasal mucosa, while rhinosinusitis or sinusitis affects the nose and paranasal sinuses, including frontal, ethmoid, maxillary, and sphenoid sinuses. Nasopharyngitis (rhinopharyngitis or the common cold) affects the nares, pharynx, hypopharynx, uvula, and tonsils generally. Without involving the nose, pharyngitis inflames the pharynx, hypopharynx, uvula, and tonsils. Similarly, epiglottitis (supraglottitis) inflames the superior portion of the larynx and supraglottic area; laryngitis is in the larynx; laryngotracheitis is in the larynx, trachea, and subglottic area; and tracheitis is in the trachea and subglottic area.

Streptococcal pharyngitis, also known as strep throat, is an infection of the back of the throat including the tonsils caused by "group A streptococcus" (GAS). Common symptoms include fever, sore throat, red tonsils, and enlarged lymph nodes in the neck. A headache, and nausea or vomiting may also occur. Some develop a sandpaper-like rash which is known as scarlet fever. Symptoms typically begin one to three days after exposure and last seven to ten days.

Strep throat is spread by respiratory droplets from an infected person. It may be spread directly or by touching something that has droplets on it and then touching the mouth, nose, or eyes. Some people may carry the bacteria without symptoms. It may also be spread by skin infected with group A strep. The diagnosis is made based on the results of a rapid antigen detection test or throat culture in those who have symptoms.

Prevention is by washing hands and not sharing eating utensils. There is no vaccine for the disease. Treatment with antibiotics is only recommended in those with a confirmed diagnosis. Those infected should stay away from other people for at least 24 hours after starting treatment. Pain can be treated with paracetamol (acetaminophen) and nonsteroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen.

Strep throat is a common bacterial infection in children. It is the cause of 15–40% of sore throats among children and 5–15% among adults. Cases are more common in late winter and early spring. Potential complications include rheumatic fever and peritonsillar abscess.

It is caused by bacteria which if untreated can lead to many other problems in the body. Strep throat is most common in childhood but can affect people of all ages. It may present with throat pain, difficulty swallowing, painful and swollen tonsils, fever, headache, skin rash and flu. The diagnosis of strep throat is straight forward and the treatment requires a course of penicillin. However, if the treatment is not adequate, rheumatic fever can occur with resultant damage to the heart valves.

Also called rhinorrhea, is a very common medical disorder that occurs when the nasal tissues are congested and the excess fluid runs either at the back of the throat or out of the nose. Post-nasal drip can be caused by the common cold, allergies to dust, smoking, or pet dander. Even spicy foods can sometimes cause post-nasal drip. Runny nose is not life-threatening but can be uncomfortable and socially unacceptable.

Unlike tonsillitis, which is more common in the children, PTA has a more even age spread, from children to adults. Symptoms start appearing two to eight days before the formation of an abscess. A progressively severe sore throat on one side and pain during swallowing (odynophagia) usually are the earliest symptoms. As the abscess develops, persistent pain in the peritonsillar area, fever, a general sense of feeling unwell, headache and a distortion of vowels informally known as "hot potato voice" may appear. Neck pain associated with tender, swollen lymph nodes, referred ear pain and foul breath are also common. While these signs may be present in tonsillitis itself, a PTA should be specifically considered if there is limited ability to open the mouth (trismus).

Physical signs of a peritonsillar abscess include redness and swelling in the tonsillar area of the affected side and swelling of the jugulodigastric lymph nodes. The uvula may be displaced towards the unaffected side.

The typical symptoms of a cold include a cough, a runny nose, nasal congestion and a sore throat, sometimes accompanied by muscle ache, fatigue, headache, and loss of appetite. A sore throat is present in about 40% of cases and a cough in about 50%, while muscle ache occurs in about half. In adults, a fever is generally not present but it is common in infants and young children. The cough is usually mild compared to that accompanying influenza. While a cough and a fever indicate a higher likelihood of influenza in adults, a great deal of similarity exists between these two conditions. A number of the viruses that cause the common cold may also result in asymptomatic infections.

The color of the sputum or nasal secretion may vary from clear to yellow to green and does not indicate the class of agent causing the infection.

A cold usually begins with fatigue, a feeling of being chilled, sneezing, and a headache, followed in a couple of days by a runny nose and cough. Symptoms may begin within sixteen hours of exposure and typically peak two to four days after onset. They usually resolve in seven to ten days, but some can last for up to three weeks. The average duration of cough is eighteen days and in some cases people develop a post-viral cough which can linger after the infection is gone. In children, the cough lasts for more than ten days in 35–40% of cases and continues for more than 25 days in 10%.

Peritonsillar abscess (PTA), also known as a quinsy, is pus due to an infection behind the tonsil. Symptoms include fever, throat pain, trouble opening the mouth, and a change to the voice. Pain is usually worse on one side. Complications may include blockage of the airway or aspiration pneumonitis.

They are typically due to infection by a number of types of bacteria. Often it follows streptococcal pharyngitis. They do not typically occur in those who have had a tonsillectomy. Diagnosis is usually based on the symptoms. Medical imaging may be done to rule out complications.

Treatment is by removing the pus, antibiotics, sufficient fluids, and pain medication. Steroids may also be useful. Admission to hospital is generally not needed. In the United States about 3 per 10,000 people per year are affected. Young adults are most commonly affected.

Acute rheumatic fever (ARF) is a complication of respiratory infections caused by GAS. The M-protein generates antibodies that cross-react with autoantigens on interstitial connective tissue, in particular of the endocardium and synovium, that can lead to significant clinical illness.

Although common in developing countries, ARF is rare in the United States, possibly secondary to improved antibiotic treatment, with small isolated outbreaks reported only occasionally. It is most common among children between 5 and 15 years old and occurs 1–3 weeks after an untreated GAS pharyngitis.

ARF is often clinically diagnosed based on Jones Criteria, which include: pancarditis, migratory polyarthritis of large joints, subcutaneous nodules, erythema marginatum, and sydenham chorea (involuntary, purposeless movement). The most common clinical finding is a migratory arthritis involving multiple joints.

Other indicators of GAS infection such as a DNAase or ASO serology test must confirm the GAS infection. Other minor Jones Criteria are fever, elevated ESR and arthralgia. One of the most serious complications is pancarditis, or inflammation of all three heart tissues. A fibrinous pericarditis can develop with a classic friction rub that can be auscultated. This will give increasing pain upon reclining.

Further endocarditis can develop with aseptic vegetations along the valve closure lines, in particular the mitral valve. Chronic rheumatic heart disease mostly affects the mitral valve, which can become thickened with calcification of the leaflets, often causing fusion of the commissures and chordae tendineae.

Other findings of ARF include erythema marginatum (usually over the spine or other bony areas) and a red expanding rash on the trunk and extremities that recurs over weeks to months. Because of the different ways ARF presents itself, the disease may be difficult to diagnose.

A neurological disorder, Sydenham chorea, can occur months after an initial attack, causing jerky involuntary movements, muscle weakness, slurred speech, and personality changes. Initial episodes of ARF as well as recurrences can be prevented by treatment with appropriate antibiotics.

It is important to distinguish ARF from rheumatic heart disease. ARF is an acute inflammatory reaction with pathognomonic Aschoff bodies histologically and RHD is a non-inflammatory sequela of ARF.

Post-streptococcal glomerulonephritis (PSGN) is an uncommon complication of either a strep throat or a streptococcal skin infection. It is classified as a type III hypersensitivity reaction. Symptoms of PSGN develop within 10 days following a strep throat or 3 weeks following a GAS skin infection. PSGN involves inflammation of the kidney. Symptoms include pale skin, lethargy, loss of appetite, headache, and dull back pain. Clinical findings may include dark-colored urine, swelling of different parts of the body (edema), and high blood pressure. Treatment of PSGN consists of supportive care.

In adolescence and young adulthood, the disease presents with a characteristic triad:

- Fever – usually lasting 14 days; often mild

- Sore throat – usually severe for 3–5 days, before resolving in the next 7–10 days.

- Swollen glands – mobile; usually located around the back of the neck (posterior cervical lymph nodes) and sometimes throughout the body.

Another major symptom is feeling tired. Headaches are common, and abdominal pains with nausea or vomiting sometimes also occur. Symptoms most often disappear after about 2–4 weeks. However, fatigue and a general feeling of being unwell (malaise) may sometimes last for months. Fatigue lasts more than one month in an estimated 28% of cases. Mild fever, swollen neck glands and body aches may also persist beyond 4 weeks. Most people are able to resume their usual activities within 2–3 months.

The most prominent sign of the disease is often the pharyngitis, which is frequently accompanied by enlarged tonsils with pus—an exudate similar to that seen in cases of strep throat. In about 50% of cases, small reddish-purple spots called petechiae can be seen on the roof of the mouth. Palatal enanthem can also occur, but is relatively uncommon.

Spleen enlargement is common in the second and third weeks, although this may not be apparent on physical examination. Rarely the spleen may rupture. There may also be some enlargement of the liver. Jaundice occurs only occasionally.

A small minority of people spontaneously present a rash, usually on the arms or trunk, which can be macular (morbilliform) or papular. Almost all people given amoxicillin or ampicillin eventually develop a generalized, itchy maculopapular rash, which however does not imply that the person will have adverse reactions to penicillins again in the future. Occasional cases of erythema nodosum and erythema multiforme have been reported.

Infectious mononucleosis mainly affects younger adults. When older adults do catch the disease, they less often have characteristic signs and symptoms such as the sore throat and lymphadenopathy. Instead, they may primarily experience prolonged fever, fatigue, malaise and body pains. They are more likely to have liver enlargement and jaundice. People over 40 years of age are more likely to develop serious illness. (See Prognosis.)

"Pharyngoconjunctival fever" is a specific presentation of adenovirus infection, manifested as:

- high fever that lasts 4–5 days

- pharyngitis (sore throat)

- conjunctivitis (inflamed eyes, usually without pus formation like pink eye)

- enlargement of the lymph nodes of the neck

- headache, malaise, and weakness

- Incubation period of 5–9 days

It usually occurs in the age group 5–18. It is often found in summer camps and during the spring and fall in schools. In Japan, the illness is commonly referred to as "pool fever" as it is often spread via public swimming pools.

Catarrh , or catarrhal inflammation, is inflammation of the mucous membranes in one of the airways or cavities of the body, usually with reference to the throat and paranasal sinuses. It can result in a thick exudate of mucus and white blood cells caused by the swelling of the mucous membranes in the head in response to an infection. It is a symptom usually associated with the common cold, pharyngitis, and chesty coughs, but it can also be found in patients with adenoiditis, otitis media, sinusitis or tonsillitis. The phlegm produced by catarrh may either discharge or cause a blockage that may become chronic.

The word "catarrh" was widely used in medicine since before the era of medical science, which explains why it has various senses and in older texts may be synonymous with, or vaguely indistinguishable from, common cold, nasopharyngitis, pharyngitis, rhinitis, or sinusitis. The word is no longer as widely used in American medical practice, mostly because more precise words are available for any particular pathosis. Indeed, to the extent that it is still used, it is no longer viewed nosologically as a disease entity but instead as a symptom, a sign, or a syndrome of both. The term "catarrh" is found in medical sources from the United Kingdom. The word has also been common in the folk medicine of Appalachia, where medicinal plants have been used to treat the inflammation and drainage associated with the condition.

Due to the human ear's function of regulating the pressure within the head region, catarrh blockage may cause discomfort during changes in atmospheric pressure.

The key symptoms of PFAPA are those in its name: periodic high fever at intervals of about 3–5 weeks, as well as aphthous ulcers, pharyngitis and/or adenitis. In between episodes, and even during the episodes, the children appear healthy. At least 6 months of episodes. Diagnosis requires recurrent negative throat cultures and that other causes (such as EBV, CMV, FMF) be excluded.

Apart from respiratory involvement, illnesses and presentations of adenovirus include gastroenteritis, conjunctivitis, cystitis, and rash illness. Symptoms of respiratory illness caused by adenovirus infection range from the common cold syndrome to pneumonia, croup, and bronchitis. Patients with compromised immune systems are especially susceptible to severe complications of adenovirus infection. Acute respiratory disease (ARD), first recognized among military recruits during World War II, can be caused by adenovirus infections during conditions of crowding and stress.

Rhinitis, also known as coryza, is irritation and inflammation of the mucous membrane inside the nose. Common symptoms are a stuffy nose, runny nose, sneezing, and post-nasal drip.

The inflammation is caused by viruses, bacteria, irritants or allergens. The most common kind of rhinitis is allergic rhinitis, which is usually triggered by airborne allergens such as pollen and dander. Allergic rhinitis may cause additional symptoms, such as sneezing and nasal itching, coughing, headache, fatigue, malaise, and cognitive impairment. The allergens may also affect the eyes, causing watery, reddened, or itchy eyes and puffiness around the eyes. The inflammation results in the generation of large amounts of mucus, commonly producing a runny nose, as well as a stuffy nose and post-nasal drip. In the case of allergic rhinitis, the inflammation is caused by the degranulation of mast cells in the nose. When mast cells degranulate, they release histamine and other chemicals, starting an inflammatory process that can cause symptoms outside the nose, such as fatigue and malaise. In the case of infectious rhinitis, it may occasionally lead to pneumonia, either viral or bacterial. Sneezing also occurs in infectious rhinitis to expel bacteria and viruses from the respiratory system.

Rhinitis is very common. Allergic rhinitis is more common in some countries than others; in the United States, about 10%–30% of adults are affected annually.

Rhinitis is commonly caused by a viral or bacterial infection, including the common cold, which is caused by Rhinoviruses, Coronaviruses, and influenza viruses, others caused by adenoviruses, human parainfluenza viruses, human respiratory syncytial virus, enteroviruses other than rhinoviruses, metapneumovirus, and measles virus, or bacterial sinusitis, which is commonly caused by "Streptococcus pneumoniae", "Haemophilus influenzae", and "Moraxella catarrhalis". Symptoms of the common cold include rhinorrhea, sneezing, sore throat (pharyngitis), cough, congestion, and slight headache.