Hyperalgesia can sometimes occur after surgery or from health
issues like fibromyalgia or shingles. It can also happen if you take opioids for a
long time or start taking high doses of them quickly. Then it's called
opioid-induced hyperalgesia (OIH).
In OIH, a person taking opioids becomes more sensitive to pain
rather than feeling relief from pain. Taking more of the opioid can even make the
pain worse. OIH is not the same as tolerance or addiction. People who build up a
tolerance for an opioid may ease their pain by taking more of it.
An opioid is a strong type of narcotic pain medicine. Some
examples are morphine, fentanyl, hydrocodone, and oxycodone. These medicines can
help ease pain after surgery and are also useful for chronic pain or health problems
like cancer. Opioids can be very addictive and may also have side effects, such as
nausea, constipation, and OIH.