Chills are defined as episodes of shivering that are accompanied by feeling very cold and paleness. Chills are caused by rapid successions of muscle contractions and relaxation. The trigger of chills is the body's attempt to increase body heat when it feels cold. Chills usually occur as one of the first symptoms of an infection and are often accompanied by fever.
The common cold is a common infection of the upper respiratory tract that can be caused by more than 200 viruses, but is most commonly caused by the rhinovirus. MayoClinic.com notes that, on average, adults experience a cold two to four times per year. Colds are contagious and can be spread through airborne particles or direct contact with an infected individual. Common symptoms of a cold include runny or congested nose, sore throat, cough, body aches, headache, sneezing, watery eyes, fatigue and a low fever accompanied by mild chills. There is no cure for the common cold, but over-the-counter medications such as nasal sprays and pain relievers can improve symptoms until the infection goes away.
The tonsils, which are part of the lymphatic system, are large lymph nodes whose main function is to filter out bacteria and microorganisms that enter the mouth. Occasionally, the tonsils can become infected. This condition, called tonsillitis, may affect the throat and pharynx as well as the tonsils. Symptoms of tonsillitis include ear pain, difficulty swallowing, fever, chills, headache, persistent sore throat, jaw tenderness and loss of voice, according to MedlinePlus. Treatment for tonsillitis depends on the infectious organism causing the infection. If the infection is caused by bacteria, antibiotics can help treat it. Viral infections cannot be treated with medications.
Influenza, also referred to as the flu, is a contagious respiratory infection caused by any of the influenza viruses. Severity of influenza differs between individuals and may be considered a medical emergency in infants or elderly adults, according to the Centers for Disease Control and Prevention. Common symptoms of influenza include fever, chills, cough, sore throat, runny nose, muscle and body aches, headaches and fatigue. The CDC notes that some, but not all, people experience vomiting and diarrhea as well. There is no treatment for influenza, but most people recover on their own anywhere from a few days to two weeks. Possible complications, such as bronchitis and pneumonia, may occur in some high-risk individuals. Treatment is necessary if these conditions develop.