There are many reasons for headache, nausea and chills, mainly including the following: 1. Headache, nausea and chills are mostly caused by the cold, once a person has a cold, there will be the role of germs toxicity, which will make a person appear headache, nausea and chills this feeling. Under normal circumstances, once a person has a fever, it is often accompanied by chills, often alternating between fever and chills. Cold to germs can invade the central nervous system, will lead to the phenomenon of headache, this situation can be alleviated by treating the cold; 2, headache, nausea, chills may also be a reaction to poisoning, common gas poisoning, etc., the patient will appear headache, nausea, chills this phenomenon, this time the patient should be moved to a fresh air place or give the patient timely oxygen, can be a good recovery; 3 The headache, nausea, chills may also be caused by gastrointestinal diseases, such as acute gastroenteritis after eating bad stomach, many people will have headaches, nausea, chills and other symptoms.