Final answer:
The term 'algesia' refers to pain or sensitivity to pain, while 'analgesic' is a substance that reduces pain. A narcotic can also reduce pain but may cause drowsiness or loss of consciousness in higher doses. Congenital analgesia is a genetic condition resulting in an absence of pain sensation.
Step-by-step explanation:
The terms 'alges/o' and '-algesia' relate to pain. The prefix 'alges/' indicates pain, while the suffix '-algesia' is used to denote sensitivity to pain. Therefore, among the options provided, 'algesia' refers to condition number 3) algesia, which means pain or sensitivity to pain, as opposed to 'analgesia' which denotes an absence or reduction of pain. The medical term 'analgesic' refers to a substance that reduces pain without causing loss of consciousness, while the term 'narcotic' in higher doses may cause drowsiness and even loss of consciousness.
One genetic disorder related to this topic is congenital insensitivity to pain or congenital analgesia, which results in an individual's inability to experience pain. This is an example of an extreme form of analgesia that is present from birth due to a genetic mutation.