The most common MRI side effects are those related to lying in a small space for a long period of time and may include dizziness, backaches, and fatigue. More serious side effects may occur as a reaction to any contrast medium used for the MRI. In very rare circumstances, if a piece of metal is in the body, the MRI machine may force the object to move within the body, causing serious damage. This is a very rare side effect, as there are stringent precautions in place to protect against this kind of accident.
Commonly, people experience MRI side effects that seem to be caused by the effects of magnetic resonance imaging but are in fact caused by lying very still for long periods of time. The dizziness and backaches reported by some patients are almost certainly caused by lying still on a hard surface for an hour or more. Fatigue after an MRI is often caused by the stress related to the taking of the images, which can be more tiring than is apparent during the procedure. MRI side effects such as headaches are often related to the loud noises one hears during an MRI and are more common for people who also experience migraines.
Some people experience mild MRI side effects usually resembling an allergic reaction when a contrast medium is used. Very serious MRI side effects can occur when a patient has severe kidney failure and is exposed to a contrast medium containing gadolinium. This side effect is a disease called nephrogenic systemic fibrosis, which is incurable and sometimes fatal. It is relatively unlikely that one will experience this side effect, as renal failure is usually identified prior to an MRI involving gadolinium.
Very rarely, iron in the body will cause painful MRI side effects. Ferromagnetic objects can move forcefully from any position near an MRI machine. If they are inside the body, they can cause major harm to internal organs. A person with metal fillings in his or her teeth may feel slight tingling, but minor dental fixtures are usually not problematic for the procedure.
The most common side effect of an MRI appears to be an elevated sensitivity to possible health problems. An MRI machine is a stressful and often unfamiliar piece of technology, and many people become very concerned about sensations that would normally not be considered worrisome. Perceived tingling or dizziness that normally goes unnoticed or any sensation of pain becomes a source of major concern. The perceived possibility that there have been major side effects causes symptoms of panic as well. These side effects can be avoided by talking with a trusted doctor and recognizing that an MRI is a very safe procedure.