Cilnidipine is a calcium channel blocker used in the treatment of patients with high blood pressure and has antihypertensive properties. It may cause urinary system, allergic reaction, circulatory system, nervous system, blood system and other side effects. 1. Urinary system: some patients may have frequent urination, and may also have abnormal laboratory tests, such as positive uric acid, creatine, urinary precipitation and urinary protein. 2. Allergy: mainly manifested as drug rash, redness, swelling and itching. If allergic reaction occurs, the drug should be stopped immediately and a doctor should be consulted promptly. 3. Circulatory system: It may cause circulatory system abnormality, mainly manifested as flushing, palpitation, parchedness, ECG abnormality, low blood pressure, chest pain, chills and so on. 4. Nervous system: Nervous system may cause dizziness, headache, drowsiness, insomnia, stiffness of shoulder muscles, and forgetfulness. 5. Blood system: Causes abnormalities in the blood system, which may include abnormal red blood cells, eosinophils and lymphocytes, thrombocytopenia, abnormal white blood cell count, neutrophilic leukocytes, and so on. In addition to this, Cilnidipine side effects include digestive system reactions, hematologic abnormalities and other adverse reactions. Clinically, it is forbidden to use it for pregnant women, those who are allergic to the components of the product and those who work at high altitude. Therefore, it should be used under the guidance of a professional doctor and in accordance with medical advice.