Left chest pain when sleeping on the side is mostly considered coronary heart disease, intercostal neuralgia, pleurisy, trauma, etc. The treatment includes medication, surgery, etc., and the use of medication should be in accordance with the doctor’s instructions. 1. Coronary heart disease: myocardial ischemia causing anterior chest pain. Patients should immediately bed rest, sublingual nitroglycerin, or use drugs to reduce myocardial oxygen consumption, such as metoprolol. Surgery, such as percutaneous coronary intervention or coronary artery bypass grafting, may be needed. 2. Intercostal neuralgia: If it is caused by herpes zoster infection, antiviral drugs such as acyclovir can be used, and non-steroidal anti-inflammatory drugs such as ibuprofen can be used for severe pain. 3. Pleurisy: if it is tuberculous pleurisy, regular anti-tuberculosis treatment, such as anti-tuberculosis drugs isoniazid, rifampicin, etc., and closed drainage of thoracic cavity is feasible when there is pleural effusion. 4. Trauma: impact or extrusion injuries resulting in local soft tissue injury or rib fractures, feasible elastic band external fixation, pain severe use of non-steroidal anti-inflammatory drugs, such as ibuprofen, etc., the condition requires surgical treatment. Sleeping on the side of the left chest pain can also be seen in other causes, it is recommended that the patient timely medical treatment, so as not to delay the condition.