Diclofenac is the generic name for a prescription medicine to relieve the symptoms of osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis. If you take this drug, you will be at greater risk for a stroke or heart attack. It can also cause bleeding, ulcers and even holes in the stomach. Unfortunately, you may not even have any symptoms before you are in grave medical danger. The list of side effects is long, if you take Diclofenac tablets. If you decide to take the chance, make sure you are closely monitored by your doctor. Also, let your doctor know immediately, if you are not feeling well, because some of these side effects of Diclofenac can cause death.