The combining forms alges- and -algia refer to pain, painful conditions, or heightened sensitivity to pain. These appear frequently in neurology, orthopedics, and general medicine.
“pain,” “sensitivity to pain,” “grief”
The word entered English in the 1780s as a combining form and suffix (suffix/noun-forming), borrowed from Modern Latin algos, from Greek ἄλγος — literally “pain.” The root algos (“pain”) connects algia- to the entire pain and sensation roots: neuralgia (neur- + -algia → nerve pain), myalgia (myo- + -algia → muscle pain), and analgesic (an- + alg- → without pain). The combining form/suffixalgia- is extremely productive across almost all medical specialties: e.g., arthralgia, fibromyalgia, and hyperalgesia.