The tonsils are two oval-shaped lumps of tissue that sit on either side of the back of the throat. Tonsillitis is inflammation of the tonsils, usually resulting from a viral or bacterial infection. The location of these organs means most symptoms of tonsillitis impact the throat and surrounding areas. Because the tonsils act as defense mechanisms that protect against infection, tonsillitis can affect various aspects of the lymphatic system, as well.

Viral Infection

As much as 80% of tonsillitis cases are the result of viral infections. Usually, the same viruses that cause the common cold also lead to tonsillitis, though many others can be responsible, as well. The viruses that most frequently cause tonsillitis are rhinovirus, influenza, adenovirus, and coronavirus. Occasionally, the condition is due to more serious infection, such as HIV or herpes simplex virus. White blood cells within the tonsils destroy the viruses, but because the organs act as filters, they are particularly vulnerable. Some symptoms of tonsillitis occur directly from the infection, while others develop because of the immune response.

Bacterial Infection

Tonsillitis cases are the result of bacterial infections in five to 36% of cases. In most instances, group A streptococcus, the same bacterium that causes strep throat, is responsible. Some researchers note a link between anaerobic bacteria and tonsillitis, a connection that could lead to a more accurate understanding and effective treatment of the condition. Bacterial tonsillitis is most common in children between the ages of five and 15, while viral infections typically affect younger individuals.

Redness and Swelling

The most common symptoms of tonsillitis are redness and swelling of the tonsils. These are two of the five classic signs of inflammation. The redness is due to increased blood flow to the affected area. Swelling is usually the result of fluid buildup. In some cases, the tonsils may swell enough to be observable externally. One of the possible dangers of tonsillitis is severe swelling that inhibits airflow that can compromise breathing.

Sore Throat

Another common symptom of tonsillitis is a sore throat. Inflammation can cause minor to severe pain, especially around the tonsils. Additionally, the infection can spread beyond the tonsils to other areas of the throat and runs the risk of becoming pharyngitis or inflammation of the throat.

Yellow or White Coating

People with tonsillitis can develop a yellow or white coating, called exudate, on their tonsils that looks like streaks or patches. As the tonsils try to fight the infection, they swell and produce pus that can collect on the outside of the organs, creating this coating. This can cause bad breath or bad tastes when swallowing. Acute tonsillitis can be complicated by the formation of an abscess, a pocket of puss that accumulates within or around the tonsils.

Fever

Many people develop fevers when they have tonsillitis. This is not a result of the infection itself, but of the immune system trying to fight it. Some doctors believe that fevers kill dangerous viruses and bacteria that are sensitive to temperature changes. Most tonsillitis fevers are mild and resolve within a few days. However, if a person’s fever exceeds 103 degrees F, it is a sign of a medical emergency.

Difficulty Swallowing

Individuals with tonsillitis often have difficulty swallowing due to a combination of effects. Sore throats make it painful to swallow, and inflammation can make it difficult, while pus affects the taste of food, discouraging eating. People with severe tonsillitis often lose some weight as the condition progresses because they avoid food.

Tender Lymph Nodes

There are many lymph nodes within the head and neck. These small tissues act as filters and help fight infection. Because the tonsils consist of tissue similar to that of the lymph nodes, they react similarly. Tonsillitis that spreads beyond the tonsils may cause the lymph nodes to swell, becoming painful to the touch and, like the tonsils, affecting swallowing. Swollen lymph nodes in the neck may also be externally visible.

Malaise

Medical experts use the term “malaise” to refer to a general sense of discomfort, uneasiness, or pain. It is often the first sign of an infection. As the body prepares to fight viruses or bacteria, people can often feel their immune system gearing up. Researchers believe malaise is the result of the immune system and proinflammatory cytokines becoming active.

Airway Obstruction

With modern medical treatment options, serious complications fromacute tonsillitis are rare. Nonetheless, airway obstruction due to swelling of the tonsils is a medical emergency. Signs that the airway is compromised include high-pitched, labored breathing (stridor), as well as drooling, a hoarse voice, and flaring of the nostrils. Seek immediate medical assistance if these signs are present.