Lying down chest pain may be caused by overwork, trauma, pleurisy, viral myocarditis and other reasons. 1. Overexertion: if the patient has been doing heavy physical labor or strenuous exercise for a long time, it may cause the chest muscles to be overworked, which may lead to the symptom of chest pain while lying down. 2. Trauma: Lying down chest pain may be caused by trauma, when the patient has chest wall, rib cartilage or chest soft tissue injury, lying down chest pain may occur. 3. Pleurisy: lying down chest pain may be caused by pleurisy, chest pain is the most common symptom of pleurisy, and the patient may also be accompanied by coughing, chest tightness, shortness of breath and even dyspnea and other symptoms. 4. viral myocarditis: lying down chest pain may also be caused by viral myocarditis, viral myocarditis patients may appear chest pain symptoms, accompanied by fever, body aches, nausea and vomiting and other symptoms. When the patient has the symptom of lying down chest pain, if it is not relieved for a long time or even progressive aggravation, it is recommended to go to the hospital in time, under the guidance of the doctor reasonable treatment.