Diltiazem is a medication primarily used to treat high blood pressure and certain heart conditions, such as angina and arrhythmias. It belongs to a class of drugs known as calcium channel blockers, which work by relaxing the blood vessels and improving blood flow. This helps to lower blood pressure and reduce the workload on the heart. Diltiazem is available in various forms, including tablets and extended-release capsules. Patients are usually advised to take it as prescribed by their healthcare provider, and it may be combined with other medications for optimal management of cardiovascular conditions. Common side effects can include dizziness, headache, and swelling in the legs.