The causes of dizziness, dullness and head distension in clinical practice are mainly considered in the following aspects: Firstly, it may be caused by environmental factors, such as patients in a hot environment or in an air-conditioned environment with poor air circulation, which will lead to brain tissue in chronic hypoxia, and patients will have dizziness, dullness and head distension. Secondly, if the patient has cerebral arteriosclerosis and severe narrowing of cerebral blood vessels, resulting in chronic ischemia and hypoxia of brain tissue, he or she will also have symptoms of dizziness, dullness and head swelling, which can be clarified by doing transcranial Doppler examination. Thirdly, if the patient has hypertension, poorly controlled blood pressure and elevated blood pressure will cause dizziness, dullness, and head swelling. Fourthly, if the patient has heart disease, such as coronary artery disease, myocardial ischemia, and frequent premature ventricular contractions, it may also cause the patient to have cardiogenic cerebral blood supply deficiency, and the above symptoms may be clarified by doing cardiac ultrasound and electrocardiogram.