Calcium channel blockers (CCBs) are prescribed for a variety of conditions, including:

• High blood pressure (hypertension). Higher than normal blood pressure (the force of blood against the artery walls). While CCBs lower blood pressure on their own, they are sometimes combined with other antihypertensive medications (most commonly diuretics). CCBs are not usually considered the first-line treatment of high blood pressure.
  
  
• Angina. A type of chest pain, pressure or discomfort that is associated with coronary artery disease. Generally, CCBs are used only in patients with stable angina who have not responded to other forms of medication, including beta blockers or nitrates. Stable angina occurs during or after a known trigger, such as exercise or smoking. They are not prescribed for unstable angina, where pain occurs unpredictably.
  
  
• Coronary artery disease (CAD). In addition to relieving symptoms associated with CAD (e.g., angina pain), other uses for CCBs are being explored. For instance, patients who have balloon angioplasty or stenting to open clogged arteries run the risk of those arteries re-closing at a later time (a condition called restenosis). Research has suggested that CCB use can help reduce the risk of restenosis. A few studies have also suggested that certain CCBs may slow the progression of atherosclerosis, a disease in which the coronary arteries are gradually clogged with hardened plaque deposits.
  
  
• Coronary spasm. An abnormal tightening of the muscle fibers of the coronary artery. Calcium channel blockers are usually the first medication used in treating chest pain caused by a coronary spasm.
  
  
• Arrhythmia. An abnormal heartbeat resulting from any change or malfunction in the heart’s electrical system. Certain types of calcium channel blockers (e.g., verapamil, diliatzem) may be used to treat a form of arrhythmia called supraventricular tachycardia – a fast heart beat originating in the upper chambers of the heart (atria) or A-V node. Also, CCBs are used to treat a type of arrhythmia called atrial fibrillation. These drugs are not generally used to treat arrhythmias that originate in the lower chambers of the heart (ventricles).

• Past subendocardial infarction. A type of heart attack. CCBs may be prescribed to help reduce a person’s risk of having another subendocardial infarction. However, these drugs are not indicated after most types of heart attacks.
  
  
• Subarachnoid hemorrhage. A kind of ischemic stroke characterized by bleeding between the brain and the skull that is usually caused by a ruptured aneurysm. Calcium channel blockers may be used in both the prevention and treatment of this life-threatening condition.
  
  
• Hypertrophic cardiomyopathy. A disease in which the heart muscle is significantly thickened, characterized by abnormally strong contractions and impaired relaxation. CCBs can help people with this disease by reducing the heart’s workload. CCBs may also reduce the severity of obstructions to the left ventricular outflow tract, which is frequently observed in these patients.

• Raynaud syndrome. A disease that affects the small arteries in the extremities. People with Raynaud's suffer from episodes of ischemia (lack of blood flow) that causes the affected areas to turn blue and white. These episodes may be triggered by exposure to cold.
  
  
• Migraine or cluster headaches.
  
  
• Esophageal spasm.
  
  
• Preterm (premature) labor.