Health Topics
May 2003
NIAMS
Pain Research: An Overview
About Pain
Throbbing, burning, aching, stinging–the terms patients
use to describe pain are often different because pain is personal and
subjective and influenced by age, gender, race/ethnicity, and psychosocial
factors. The International Association for the Study of Pain defines
it as an unpleasant experience associated with actual or potential tissue
damage to a person's body.
There are two basic forms of physical pain: acute and
chronic. Acute pain, for the most part, results from disease, inflammation,
or injury to tissues. It is immediate and usually of a short duration.
Acute pain is a normal response to injury and may be accompanied by
anxiety or emotional distress. The cause of acute pain can usually be
diagnosed and treated.
Chronic pain is continuous pain that persists for more
than 3 months, and beyond the time of normal healing. It ranges from
mild to severe and can last weeks, months, or years to a lifetime. The
cause of chronic pain is not always evident, although it can be brought
on by chronic conditions such as arthritis and fibromyalgia. Chronic
pain can often interfere with a patient's quality of life, sleep, and
productivity.
A Symptom of Many Diseases
Pain often accompanies diseases of the bones, muscles,
joints, and skin, which affect millions of Americans. Most of these
diseases are chronic and may cause lifelong pain. In certain cases,
such as with some rheumatic diseases, the sources of pain may include
inflammation of the synovial membrane (tissue that lines the joints),
the tendons, or the ligaments; muscle strain; and muscle fatigue. A
combination of these factors contributes to the intensity of the pain.
Muscle inflammation characterizes other painful disorders such as polymyositis
(characterized by inflamed and tender muscles throughout the body, particularly
those of the shoulder and hip) and dermatomyositis (characterized by
patchy red rashes around the knuckles, eyes, and other parts of the
body, along with chronic inflammation of the muscles).
In other cases, such as with myofascial pain syndromes,
the cause of the pain is unknown. Myofascial pain syndromes affect sensitive
areas known as trigger points, located within the body's muscles. It
is important to consult with a physician to help determine the cause
and treatment for your pain.
Talking to Your Doctor About Pain
Pain is managed by the patient and his or her health care providers.
In order to help assess the cause and treatment for your pain, a doctor
will usually do the following:
- Take your medical history
- Review any medications you are using
- Conduct a physical examination to determine the causes of pain and how this pain is affecting your ability to function
- Take blood and/or urine samples and request necessary laboratory work
- Ask you to have x rays taken or undergo other imaging procedures such as a CAT (computerized axial tomography) scan or MRI (magnetic resonance imaging)
There is no medical test that can convey the level of pain you
are feeling. Only you can describe your pain. In order to provide an
accurate description of your pain, it may be helpful to share the answers
to the following questions with your doctor:
- How long have you had pain?
- Where is the pain located?
- Does the pain come and go or is it continuous?
- What makes the pain better or worse?
- Has the pain changed since your last visit with your doctor?
- What medications or treatments have you tried for the pain?
After you have been evaluated by your doctor, he or she will discuss
the findings with you and design a comprehensive management plan for
your pain. There are currently many treatment options available for
pain, and scientists believe that research can help lead to more and
better treatments for pain in the future.
Research on Pain
Pain research is conducted and funded by the Department of Health
and Human Services' National Institutes of Health (NIH) by many of its
institutes and centers, including the National Institute of Arthritis
and Musculoskeletal and Skin Diseases (NIAMS). Although some of this
research on pain is not linked to any disease specifically, certain
aspects of pain research are applicable to many diseases.
The research on pain supported by NIAMS covers a broad spectrum
from basic research to clinical studies to behavioral interventions.
This research is needed to:
- determine the most effective drug and nondrug therapies and interventions, including complementary and alternative treatments
- remove barriers to effective treatment
- identify assessment tools for patients unable to describe their pain
- identify effective pain management strategies for individuals with disabilities and in underserved populations
NIAMS currently supports research on pain conducted by scientists
in laboratories on the NIH campus, and through grants and contracts
to researchers in universities, research institutions, and medical centers
across the United States. This research includes basic and behavioral
investigations, such as pain processing mechanisms in the brain and
central nervous system; stress response systems and pain; gender and
hormonal influences on pain; and coping methods for pain.
Grant and contract applications submitted to NIH go through a
two-step peer review process. Applications from researchers are first
reviewed by panels of outside experts for their scientific merit. Applications
are then reviewed by the Institute's Advisory Council, which assesses
the relevance and priority of proposed projects, and makes recommendations
on funding particular meritorious applications. This process is used
throughout NIH for applications in all diseases and areas of science.
Why is Basic Research Important to Understanding
Pain?
Basic research is work undertaken primarily to acquire new knowledge
of the biological, behavioral, and social mechanisms that underlie health
and disease. This type of research, which is often conducted using animal
models, provides the broad base of knowledge necessary to advance the
diagnosis, treatment, and prevention of many diseases. NIAMS supports
a wide and diverse body of basic research, since it is hard to know
where scientific advances will come from. Progress in one research area
provides data for other areas. Similarly, progress in areas supported
by other NIH institutes provides valuable information for diseases within
the NIAMS mission. That is why it is essential to support basic studies
across the research spectrum and to encourage sharing of knowledge from
experts in many disciplines.
Why Is Behavioral Research Important to Understanding
Pain?
Pain has a profound effect on the quality of human life. Pain
can cause disruptions in sleep, eating, mobility, and overall ability
to function. Progress is being made in understanding the physiological
mechanisms involved in pain. However, understanding individuals' pain
experience presents unique scientific challenges. The levels of pain
different people experience and their reactions to it vary widely, perhaps
due to psychological state, age, gender, social environment, and cultural
background, as well as genetic or physiological differences. Thus, the
pain experience needs to be examined at all levels of basic and clinical
research, including behavioral research, with the goal of developing
interventions to manage or prevent pain.
Behavioral and social sciences research include a wide array of
disciplines. The field uses such techniques as:
- surveys and questionnaires
- randomized clinical trials
- direct observation
- descriptive methods
- economic analyses
- laboratory and field experiments
- standardized tests
- evaluation
Highlights of Current and Planned Initiatives
NIH Pain Research Consortium.
The NIH Pain Research Consortium encourages information sharing and
collaborative research efforts across NIH in the field of pain research.
Directors of participating NIH Institutes meet to exchange information,
propose topics for workshops and conferences, and support program announcements
in the field of pain research. These meetings help to provide coordination
of pain research across all NIH components, and ensure that results
of NIH-sponsored pain research are widely communicated.
Sex and Gender Factors Affecting Women's
Health--Specialized Centers of Research (SCORS). In conjunction
with the NIH Office of Research on Women's Health and other NIH institutes,
NIAMS is co-funding research on the role of sex- and gender-related
health effects. As part of this initiative, a multidisciplinary SCOR
is devoted to studying the mechanisms of chronic pain, with special
focus on sex-related factors that influence pain and painful clinical
conditions that show a high prevalence in women. This center will help
apply basic knowledge to the study of persistent pain in humans, and
ultimately to developing new ways to diagnose and treat these conditions
in the general population.
The Management of Chronic Pain--Program
Announcement. NIAMS is co-sponsoring an announcement for grants
to study management of chronic pain across the lifespan. It has been
estimated that 4 out of every 10 people with moderate to severe pain
do not get enough relief for chronic pain. The announcement's goal is
to encourage research to find effective interventions, effective drug
and nondrug treatments, assessment tools, and management strategies
for pain.
Information Resources
National Institute of Arthritis and Musculoskeletal
and Skin Diseases
National Institutes of Health
1 AMS Circle
Bethesda, MD 20892-3675
Phone: 301-495-4484 or 877-22-NIAMS (226-4267) (free of charge)
Fax: 301-718-6366
www.niams.nih.gov
The National Institute of Arthritis and Musculoskeletal and Skin
Diseases provides information about rheumatic, bone, muscle, and skin
diseases. It distributes patient and professional education materials
and refers people to other sources of information. Additional information
and updates can also be found on the NIAMS Web site.
National Institute of Dental and Craniofacial Research
National Institutes of Health
45 Center Drive, MSC 6400
Building 45, Room 4AS-25
Bethesda, MD 20892-6400
Phone: 301-496-4261
www.nidcr.nih.gov
The National Institute of Dental and Craniofacial Research
(NIDCR) provides information about craniofacial-oral-dental diseases
and disorders. It distributes patient and professional education materials
and refers people to other sources of information. Additional information
and updates can also be found on the NIDCR Web site.
National Institute of Neurological Disorders and Stroke
National Institutes of Health
Office of Communications and Public Liaison
P.O. Box 5801
Bethesda, MD 20824
Phone: 301-496-5751 or 800-352-9424 (free of charge)
Fax: 301-402-2186
www.ninds.nih.gov
The National Institute of Neurological Disorders and Stroke
(NINDS) provides information about neurological disorders. It distributes
patient and professional education materials and refers people to other
sources of information. Additional information and updates can also
be found on the NINDS Web site.
American Chronic Pain Association
P.O. Box 850
Rocklin, CA 95677
Phone: 916-632-0922
www.theacpa.org
This association provides information on positive ways
to deal with chronic pain and can provide guidelines on selecting a
pain management center.
American Pain Society
4700 West Lake Avenue
Glenview, IL 60025-1485
Phone: 847-375-4715
www.ampainsoc.org
This society provides general information to the public
and maintains a directory of resources, including referrals to pain
centers.
National Chronic Pain Outreach Association, Inc.
7979 Old Georgetown Road, Suite 100
Bethesda, MD 20814-2429
Phone: 301-652-4948
Fax: 301-907-0745
neurosurgery.mgh.harvard.edu/ncpainoa.htm
This association operates an information clearinghouse
offering publications and cassette tapes for people with pain. It also
publishes a newsletter that includes information on pain management
techniques, coping strategies, book reviews, and support groups.
National Foundation for the Treatment of Pain
1330 Skyline Drive, Suite #21
Monterey, CA 93940
Phone: 831-655-8812
Fax: 831-655-2823
www.paincare.org
This organization provides support for patients who are
suffering from pain, their families and friends, and the physicians
who treat them. They also offer a patient forum, advocacy programs,
information, support resources, and direct medical intervention.
The mission of the National Institute of Arthritis and Musculoskeletal
and Skin Diseases (NIAMS), a part of the Department of Health and Human
Services' National Institutes of Health (NIH), is to support research
into the causes, treatment, and prevention of arthritis and musculoskeletal
and skin diseases, the training of basic and clinical scientists to
carry out this research, and the dissemination of information on research
progress in these diseases. The NIAMS Information Clearinghouse is a
public service sponsored by the Institute that provides health information
and information sources. Additional information can be found on the
NIAMS Web site at www.niams.nih.gov.