The primary contraindication is implanted electronic equipment , such as pacemakers, defibrillators, cochlear implants, pain modulators, and insulin pumps. Most of the magnets that are available will not affect pacemakers unless they are brought directly over the pacemaker. People may inadvertently place magnets next to pacemakers and not produce any significant effects. While some pacemakers are shielded it is not always known which ones will react. To avoid risk, magnets should not be used by patients with pacemakers or in bed if the spouse has one.
Pregnancy is a relative contraindication for risk management reasons.
Even with MRI there are no currently accepted risks in pregnancy. Still, avoidance is the better part of valor. Individuals with acute pain in a body cavity, not previously evaluated or diagnosed should not be using magnets. Pain like other analgesics can be masked by magnets. Acute or emergent processes may progress because magnets are so effective at pain management.