Redheads and Pain Perception

By Ellen Kuwana
Neuroscience for Kids Staff Writer
December 17, 2002

If you have red hair, you might want to talk to your anesthesiologist before having surgery--and request more anesthesia! A study has shown that women with naturally red hair require up to 20% more anesthesia than dark-haired women.

Researchers administered a commonly used inhalation anesthetic, desflurane, to 20 women (10 redheads and 10 non-redhead controls) between the ages of 19 and 40 years. The researchers then gave small electric shocks to the anesthetized women to measure their pain response. Compared to the non-redheads, the redheads required more anesthesia to reach what the experts judged an "optimum" dose. The optimum dose was determined by the amount of anesthesia needed to suppress movement in response to the small electrical shocks. Because this is a small study and only women were tested, more research needs to be done before generalizations can be made.

Everyone has a unique response to pain. Something that is unbearably painful to one person might be only mildly painful to another. Attention to pain may also influence the perception of that pain. Redheads, however, apparently feel pain more than most other people because of a quirk of genetics that is linked to having red hair.

Why would hair color matter? Scientists think that the answer involves melanin, a pigment that influences skin and hair color. Redheads have light skin because they have a defective receptor for a hormone that triggers the production of melanin. This hormone, without its receptor to bind to, may float around and bind to other receptors, interfering with receptors on brain cells, such as those that influence pain perception. Sound complicated? It is, a little.

Let's pretend that the defective receptor is like a gate with a broken lock and the hormone is a goat. Without the gate to keep the hormone where it's supposed to be, it wanders around to neighbors' yards and eats all their grass. So certain people have "damaged lawns," all because of a faulty gate.

Anesthesiology is a science and an art: it is a balance between using too little anesthetic (recalling the events of the surgery, feeling some pain) and too much anesthetic (low blood pressure and heart rate). Don't worry -- anesthesiologists go through a lot of training. Anesthesiologists must graduate from medical school (4 years) and then complete a residency where they specialize in anesthesiology (4 years). Some of these doctors then complete a fellowship (1 year), where they further specialize in fields such as pediatrics, neurology, or obstetrics.

Did You Know? An estimated 40 million anesthetics are administered each year in this country. (Source: American Society of Anesthesiologists.)


  1. Liem, E.B., Chun-Ming, L., Suleman, M.I., Doufas, A.G. and Sessler, D.I. Increased Anesthetic Requirement in Subjects with Naturally Red Hair, American Society of Anesthesiologists Meeting Abstracts, 2002.
  2. Pain from Neuroscience for Kids.
  3. "Study: Redheads need more anesthesia," by Lauran Neergaard, Seattle Times, October 15, 2002.
  4. "Red heads suffer more pain,"by Will Knight, New Scientist, October 15, 2002.

GO TO: Neuroscience In The News Explore the Nervous System Table of Contents

Send E-mail

Fill out survey

Get Newsletter

Search Pages

Take Notes