At the dentist
When you go to the dentist, you may be offered injections to numb a part of the mouth. To do this, the dentist may use an anesthetic that includes epinephrine as a component. Epinephrine is also known as adrenaline.
Unfortunately, many people with myalgic encephalomyelitis (ME/CFS) report dramatically negative effects from injections containing epinephrine. Therefore, they are advised to ask their dentist for an anesthetic without epinephrine.
General anesthesia
When undergoing surgery, a patient may receive general anesthesia, which renders the patient unconscious, local anesthesia, which only numbs a part of the body, or sedation, which merely relaxes the patient without losing consciousness.
Note that general anesthesia can have severely debilitating effects on some people with myalgic encephalomyelitis (ME/CFS). In some cases, these negative effects of general anesthesia appear to be permanent.
In general, patients are recommended to avoid general anesthesia whenever possible. Several doctors have produced documents outlining their recommendations for anesthesia and the New Jersey CFS Association has produced a card you can download and print out. (Laminating the card appears to give the recommendations more heft with hospital personnel.)

