Colds are categorized into common colds and influenza. Chills can be a pre-febrile chilling phenomenon, and can occur with both the common cold and influenza. In addition, chills may not be caused by colds, but also by hypoglycemia, hypothyroidism, or a cold environment. 1. Common cold: caused by viral infections, mainly manifested in the upper respiratory tract, such as nasal congestion and runny nose, cough and other symptoms, severe cases have fever, mild chills and so on. Mild cases do not require medication, rest and drink plenty of water. 2. Influenza: Influenza virus infection caused by chills, high fever, headache, fatigue and other symptoms of systemic poisoning, nasopharyngeal symptoms are mild. In addition to symptomatic treatment, early application of antiviral drugs. 3. Hypoglycemia: Typical symptoms include excessive sweating, pallor, fast heartbeat, hunger, etc. There will also be coldness, lack of concentration, drowsiness, and even mania. It is necessary to supplement food in time, or oral glucose solution to rapidly raise blood sugar. 4. Hypothyroidism: It is mainly manifested as weakness, coldness, weight gain, memory loss, drowsiness, etc. Physical examination reveals pale face, dry skin, facial edema, and thinning hair. It is mainly a generalized hypometabolic syndrome caused by low thyroid hormone. After the diagnosis is clear, thyroid hormone supplementation is needed. 5. Cold environment: Cold environment will lead to hypothermia and chills. Improve the living environment and pay attention to keep warm. There are many reasons for chills, and they may not be caused by colds. If the symptoms do not get better, you should consult a doctor for diagnosis and standardized treatment.