Overview
Questions and Answers About Acupuncture
Changes to This Summary (10/06/2006)
General CAM Information
Evaluation of CAM Approaches
Questions to Ask Your Health Care Provider About CAM
To Learn More About CAM

Overview

• Acupuncture applies needles, heat, pressure, and other treatments to one or more places on the skin known as acupuncture points (see Question 1 ¹).



• Acupuncture has been used in China and other Asian countries for thousands of years as part of traditional Chinese medicine (see Question 2 ²).



• Acupuncture has been used in the United States for about 200 years (see Question 2 ²).



• Acupuncture is used to treat many illnesses and ailments; however, it is mainly used to control pain, including cancer pain (see Question 2 ²).



• Acupuncture may work by causing physical responses in nerve cells, the pituitary gland, and parts of the brain (see Question 3 ³).



• Laboratory and animal studies of acupuncture for cancer treatment suggest acupuncture can reduce vomiting caused by chemotherapy and may help a person's immune system work better (see Question 5 ⁴).



• The most acupuncture research on cancer has been done in China (see Question 6 ⁵).



• Most acupuncture research with cancer patients studies the use of acupuncture to relieve symptoms caused by cancer treatment (see Question 6 ⁵).



• There is strong evidence from clinical trials that acupuncture relieves nausea and vomiting caused by chemotherapy (see Question 6 ⁵).



• It is important that acupuncture treatment be given by a qualified practitioner who uses a new set of disposable (single-use) needles for each patient (see Question 7 ⁶).

Questions and Answers About Acupuncture

1. What is acupuncture?

   Acupuncture applies needles, heat, pressure, and other treatments to certain places on the skin to cause a change in the physical functions of the body. The use of acupuncture is part of traditional Chinese medicine (TCM). TCM is a medical system that has been used for thousands of years to prevent, diagnose, and treat disease.

   Acupuncture is based on the belief that qi (vital energy) flows through the body along a network of paths, called meridians. Qi is said to affect a person’s spiritual, emotional, mental, and physical condition. According to TCM, qi has two forces, yin and yang. Yin and yang are opposite forces that work together to form a whole. The forces of yin and yang depend on each other and are made from each other in an unending cycle, such as hot and cold, day and night, and health and disease. Nothing is ever all yin or all yang, both exist in all things, including people. Many of the major organs of the body are believed to be yin-yang pairs that must be in balance to be healthy. When a person's yin and yang are not in balance, qi can become blocked. Blocked qi causes pain, illness, or other health problems. TCM uses acupuncture, diet, herbal therapy, meditation, physical exercise, and massage to restore health by unblocking qi and correcting the balance of yin and yang within the person.

   According to TCM, qi can be unblocked by using acupuncture at certain places on the skin, called acupoints. Acupoints are places where the meridians come to the surface of the body. There are more than 2,000 acupoints on the human body, with specific acupoints for each condition being treated.

2. What is the history of the discovery and use of acupuncture as a complementary and alternative treatment for cancer?

   The oldest medical book known, written in China 4000 years ago, describes the use of acupuncture to treat medical problems. The use of the treatment spread to other Asian countries and to other regions of the world, including to Europe by the 1700s. In the United States, acupuncture has been used for about 200 years.

   Research on acupuncture began in the United States in 1976. Twenty years later, the US Food and Drug Administration (FDA) approved the acupuncture needle as a medical device. Many illnesses are treated with acupuncture, but it is used mainly to control pain, including pain in cancer patients. Its primary use in cancer patients has been as an addition to conventional (standard) therapy.

3. What is the theory behind the claim that acupuncture is useful in treating cancer?

   Acupuncture may cause physical responses in nerves cells, the pituitary gland, and parts of the brain. These responses can cause the body to release proteins, hormones, and brain chemicals that control a number of body functions. It is proposed that, by these actions, acupuncture affects blood pressure and body temperature, boosts immune system activity, and causes the body's natural painkillers, such as endorphins, to be released.

4. How is acupuncture administered?

   The acupuncture method most well-known uses needles. Disposable, stainless steel needles that are slightly thicker than a human hair are inserted into the skin at acupoints. The acupuncture practitioner determines the correct acupoints to use for the problem being treated. The inserted needles may be twirled, moved up and down at different speeds and depths, heated, or charged with a weak electric current. There are other acupuncture methods that do not use needles.

   Some acupuncture techniques include the following:

   • Electroacupuncture: A procedure in which pulses of weak electrical current are sent through acupuncture needles into acupoints in the skin.
   
   
   
   • Trigger point acupuncture: The placing of acupuncture needles in a place on the skin that is away from the painful part of the body. Trigger points have to do with referred pain, pain that is not felt at the site of injury, but is sent along nerves and felt elsewhere in the body.
   
   
   
   • Laser acupuncture: The use of a weak laser beam instead of an acupuncture needle to stimulate an acupoint.
   
   
   
   • Acupuncture point injection: The use of a syringe and needle to inject drugs, vitamins, herbal extracts, or other fluids into the body at an acupoint.
   
   
   
   • Microwave acupuncture: The use of a microwave device attached to an acupuncture needle to deliver microwave radiation to an acupoint.
   
   
   
   • Acupressure: A type of massage therapy in which the fingers are used to press on an acupoint. In cancer patients, acupressure has been used to control symptoms such as pain or nausea and vomiting.
   
   
   
   • Moxibustion: A type of heat therapy in which an herb is burned above the body to warm a meridian at an acupoint and increase the flow of blood and qi. The herb may be placed directly on the skin, held close to the skin for several minutes, or placed on the tip of an acupuncture needle.
   
   
   
   • Cupping: A procedure in which a rounded glass cup is warmed and placed upside down over an area of the body, making a vacuum that holds the cup to the skin. Cupping is used to increase the flow of blood and qi. It is believed to open up the skin’s pores and allow toxins to leave the body.
   
   
   
5. Have any preclinical (laboratory or animal) studies been conducted using acupuncture?

   Scientific studies on the use of acupuncture to treat cancer and side effects of cancer began only recently. Laboratory and animal studies suggest that acupuncture can reduce vomiting caused by chemotherapy and may help the immune system be stronger during chemotherapy.

6. Have any clinical trials (research studies with people) of acupuncture been conducted?

   Most studies of the use of acupuncture in cancer patients have been done in China. In 1997, the National Institutes of Health (NIH) began evaluating the safety and effectiveness of acupuncture as a complementary and alternative therapy.

   • Studies of the effect of acupuncture on the immune system

     Human studies on the effect of acupuncture on the immune system of cancer patients showed that it improved immune system response.

   
   
   
   • Studies of the effect of acupuncture on pain

     In clinical studies, acupuncture reduced the amount of pain in some cancer patients. In one study, most of the patients treated with acupuncture were able to stop taking drugs for pain relief or to take smaller doses. The findings from these studies are not considered strong, however, because of weaknesses in study design and size. Studies using strict scientific methods are needed to prove how acupuncture affects pain.

   
   
   
   • Studies of the effect of acupuncture on nausea and vomiting caused by chemotherapy

     The strongest evidence of the effect of acupuncture has come from clinical trials on the use of acupuncture to relieve nausea and vomiting. Several types of clinical trials using different acupuncture methods showed acupuncture reduced nausea and vomiting caused by chemotherapy, surgery, and morning sickness. It appears to be more effective in preventing vomiting than in reducing nausea.

   
   
   
   • Studies of the effect of acupuncture on cancer and symptoms (other than nausea) caused by cancer treatment

     Clinical trials are studying the effects of acupuncture on cancer and symptoms caused by cancer treatment, including weight loss, cough, chest pain, fever, anxiety, depression, night sweats, hot flashes, dry mouth, speech problems, and fluid in the arms or legs. Studies have shown that, for many patients, treatment with acupuncture either relieves symptoms or keeps them from getting worse.

   
   
   
7. Have any side effects or risks been reported from acupuncture?

   There have been few complications reported. Problems are caused by using needles that are not sterile (free of germs) and from placing the needle in the wrong place, movement of the patient, or a defect in the needle. Problems include soreness and pain during treatment; feeling tired, lightheaded, or sleepy; and infections. Because chemotherapy and radiation therapy weaken the body's immune system, a strict clean needle method must be used when acupuncture treatment is given to cancer patients. It is important to seek treatment from a qualified acupuncture practitioner who uses a new set of disposable (single-use) needles for each patient.

8. Is acupuncture approved by the US Food and Drug Administration (FDA) for use as a cancer treatment in the United States?

   The FDA approved acupuncture needles for use by licensed practitioners in 1996. The FDA requires that sterile, nontoxic needles be used and that they be labeled for single use by qualified practitioners only.

Changes to This Summary (10/06/2006)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Changes were made to this summary to match those made to the health professional version.

General CAM Information

Complementary and alternative medicine (CAM)—also referred to as integrative medicine—includes a broad range of healing philosophies, approaches, and therapies. A therapy is generally called complementary when it is used in addition to conventional treatments; it is often called alternative when it is used instead of conventional treatment. (Conventional treatments are those that are widely accepted and practiced by the mainstream medical community.) Depending on how they are used, some therapies can be considered either complementary or alternative. Complementary and alternative therapies are used in an effort to prevent illness, reduce stress, prevent or reduce side effects and symptoms, or control or cure disease.

Unlike conventional treatments for cancer, complementary and alternative therapies are often not covered by insurance companies. Patients should check with their insurance provider to find out about coverage for complementary and alternative therapies.

Cancer patients considering complementary and alternative therapies should discuss this decision with their doctor, nurse, or pharmacist as they would any therapeutic approach, because some complementary and alternative therapies may interfere with their standard treatment or may be harmful when used with conventional treatment.

Evaluation of CAM Approaches

It is important that the same rigorous scientific evaluation used to assess conventional approaches be used to evaluate CAM therapies. The National Cancer Institute (NCI) and the National Center for Complementary and Alternative Medicine (NCCAM) are sponsoring a number of clinical trials (research studies) at medical centers to evaluate CAM therapies for cancer.

Conventional approaches to cancer treatment have generally been studied for safety and effectiveness through a rigorous scientific process that includes clinical trials with large numbers of patients. Less is known about the safety and effectiveness of complementary and alternative methods. Few CAM therapies have undergone rigorous evaluation. A small number of CAM therapies originally considered to be purely alternative approaches are finding a place in cancer treatment—not as cures, but as complementary therapies that may help patients feel better and recover faster. One example is acupuncture. According to a panel of experts at a National Institutes of Health (NIH) Consensus Conference in November 1997, acupuncture has been found to be effective in the management of chemotherapy-associated nausea and vomiting and in controlling pain associated with surgery. In contrast, some approaches, such as the use of laetrile, have been studied and found ineffective or potentially harmful.

The NCI Best Case Series Program ⁷, which was started in 1991, is one way CAM approaches that are being used in practice are being investigated. The program is overseen by the NCI’s Office of Cancer Complementary and Alternative Medicine (OCCAM). Health care professionals who offer alternative cancer therapies submit their patients’ medical records and related materials to OCCAM. OCCAM conducts a critical review of the materials and develops follow-up research strategies for approaches deemed to warrant NCI-initiated research.

Questions to Ask Your Health Care Provider About CAM

When considering complementary and alternative therapies, patients should ask their health care provider the following questions:

• What side effects can be expected?
• What are the risks associated with this therapy?
• Do the known benefits outweigh the risks?
• What benefits can be expected from this therapy?
• Will the therapy interfere with conventional treatment?
• Is this therapy part of a clinical trial?
• If so, who is sponsoring the trial?
• Will the therapy be covered by health insurance?

To Learn More About CAM

National Center for Complementary and Alternative Medicine (NCCAM)

The National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health (NIH) facilitates research and evaluation of complementary and alternative practices, and provides information about a variety of approaches to health professionals and the public.

NCCAM Clearinghouse

Post Office Box 7923 Gaithersburg, MD 20898–7923

Telephone: 1–888–644–6226 (toll free) 301–519–3153 (for International callers)

TTY (for deaf and hard of hearing callers): 1–866–464–3615

Fax: 1–866–464–3616

E-mail: info@nccam.nih.gov

Web site: http://nccam.nih.gov

CAM on PubMed

NCCAM and the NIH National Library of Medicine (NLM) jointly developed CAM on PubMed, a free and easy-to-use search tool for finding CAM-related journal citations. As a subset of the NLM's PubMed bibliographic database, CAM on PubMed features more than 230,000 references and abstracts for CAM-related articles from scientific journals. This database also provides links to the Web sites of over 1,800 journals, allowing users to view full-text articles. (A subscription or other fee may be required to access full-text articles.) CAM on PubMed is available through the NCCAM Web site ⁸. It can also be accessed through NLM PubMed ⁹ bibliographic database by selecting the "Limits" tab and choosing "Complementary Medicine" as a subset.

Office of Cancer Complementary and Alternative Medicine

The NCI Office of Cancer Complementary and Alternative Medicine (OCCAM) coordinates the activities of the NCI in the area of complementary and alternative medicine (CAM). OCCAM supports CAM cancer research and provides information about cancer-related CAM to health providers and the general public via the NCI Web site ¹⁰.

National Cancer Institute (NCI) Cancer Information Service

U.S. residents may call the NCI Cancer Information Service toll free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 9:00 am to 4:30 pm. Deaf and hearing impaired callers with TTY equipment may call 1-800-332-8615. A trained Cancer Information Specialist is available to answer your questions.

Food and Drug Administration

The Food and Drug Administration (FDA) regulates drugs and medical devices to ensure that they are safe and effective.

Food and Drug Administration

5600 Fishers Lane

Rockville, MD 20857

Telephone: 1–888–463–6332 (toll free)

Web site: http://www.fda.gov/

Federal Trade Commission

The Federal Trade Commission (FTC) enforces consumer protection laws. Publications available from the FTC include:

• Who Cares: Sources of Information About Health Care Products and Services
• Fraudulent Health Claims: Don’t Be Fooled

Consumer Response Center

Federal Trade Commission

CRC-240

Washington, DC 20580

Telephone: 1-877-FTC-HELP (1-877-382-4357) (toll free)

TTY (for deaf and hearing impaired callers): 202-326-2502

Web site: http://www.ftc.gov/

Glossary Terms

A specific spot on the body where an acupuncture needle may be inserted to control pain and other symptoms. Also called acupuncture point.

The application of pressure or localized massage to specific sites on the body to control symptoms such as pain or nausea. It is a type of complementary and alternative medicine.

The technique of inserting thin needles through the skin at specific points on the body to control pain and other symptoms. It is a type of complementary and alternative medicine.

A stainless steel needle that is slightly thicker than a human hair. Acupuncture needles are inserted through the skin at specific points on the body to control pain and other symptoms.

A procedure in which drugs, vitamins, herbal extracts, or other fluids are injected into the body at an acupuncture point using a syringe and needle.

A laboratory experiment using animals to study the development and progression of diseases. Animal studies also test how safe and effective new treatments are before they are tested in people.

Feelings of fear, dread, and uneasiness that may occur as a reaction to stress. A person with anxiety may sweat, feel restless and tense, and have a rapid heart beat. Extreme anxiety that happens often over time may be a sign of an anxiety disorder.

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.

The force of circulating blood on the walls of the arteries. Blood pressure is taken using two measurements: systolic (measured when the heart beats, when blood pressure is at its highest) and diastolic (measured between heart beats, when blood pressure is at its lowest). Blood pressure is written with the systolic blood pressure first, followed by the diastolic blood pressure (for example 120/80).

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

Treatment with drugs that kill cancer cells.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical trial.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical study.

Forms of treatment that are used in addition to (complementary) or instead of (alternative) standard treatments. These practices generally are not considered standard medical approaches. Standard treatments go through a long and careful research process to prove they are safe and effective, but less is known about most types of CAM. CAM may include dietary supplements, megadose vitamins, herbal preparations, special teas, acupuncture, massage therapy, magnet therapy, spiritual healing, and meditation. Also called CAM.

In medicine, a medical problem that occurs during a disease, or after a procedure or treatment. The complication may be caused by the disease, procedure, or treatment or may be unrelated to them.

A procedure in which a rounded glass cup is warmed and placed upside down over an area of the body, creating suction that holds the cup to the skin. Cupping increases the flow of blood. In traditional Chinese medicine, it is also thought to increase the flow of qi (vital energy).

A mental condition marked by ongoing feelings of sadness, despair, loss of energy, and difficulty dealing with normal daily life. Other symptoms of depression include feelings of worthlessness and hopelessness, loss of pleasure in activities, changes in eating or sleeping habits, and thoughts of death or suicide. Depression can affect anyone, and can be successfully treated. Depression affects 15-25% of cancer patients.

The process of identifying a disease, such as cancer, from its signs and symptoms.

The things a person eats and drinks.

The amount of medicine taken, or radiation given, at one time.

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

A procedure in which pulses of weak electrical current are sent through acupuncture needles into acupuncture points in the skin. This procedure is being studied in the prevention of nausea and vomiting in patients undergoing chemotherapy.

A morphine-like chemical that is made naturally in the brain and relieves pain.

In medicine, a preparation of a substance obtained from plants, animals, or bacteria and used as a drug or in drugs.

An increase in body temperature above normal (98.6 degrees F), usually caused by disease.

Liquid.

An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are safe to use and truthfully labeled. The Food and Drug Administration also makes sure that drugs, medical devices, and equipment are safe and effective, and that blood for transfusions and transplant tissue are safe. Also called FDA.

Having to do with plants.

One of many chemicals made by glands in the body. Hormones circulate in the bloodstream and control the actions of certain cells or organs. Some hormones can also be made in the laboratory.

A sudden, temporary onset of body warmth, flushing, and sweating (often associated with menopause).

The complex group of organs and cells that defends the body against infections and other diseases.

Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.

Use of a syringe and needle to push fluids or drugs into the body; often called a "shot."

Research done in a laboratory. These studies may use test tubes or animals to find out if a drug, procedure, or treatment is likely to be useful. Laboratory studies take place before any testing is done in humans.

A device that concentrates light into an intense, narrow beam used to cut or destroy tissue. It is used in microsurgery, photodynamic therapy, and for a variety of diagnostic purposes.

The use of a low-level laser beam instead of an acupuncture needle to stimulate an acupuncture point.

A treatment in which the soft tissues of the body are kneaded, rubbed, tapped, and stroked. Massage therapy may help people relax, relieve stress and pain, lower blood pressure, and improve circulation. It is being studied in the treatment of cancer symptoms such as lack of energy, pain, swelling, and depression.

An instrument, tool, machine, test kit, or implant that is used to prevent, diagnose, or treat disease or other conditions. Medical devices range from tongue depressors to heart pacemakers and medical imaging equipment.

In traditional Chinese medicine, one of 20 channels that form a network through which qi (the body's vital energy) flows and that connect the body’s acupuncture sites.

A type of acupuncture in which a microwave device is attached to an acupuncture needle to give microwave radiation at an acupuncture point.

In traditional Chinese medicine, a type of heat therapy in which an herb is burned on or above the skin to warm and stimulate an acupuncture point or affected area.

A federal agency in the U.S. that conducts biomedical research in its own laboratories; supports the research of non-Federal scientists in universities, medical schools, hospitals, and research institutions throughout the country and abroad; helps in the training of research investigators; and fosters communication of medical information. Access the National Institutes of Health Web site at http://www.nih.gov. Also called NIH.

A feeling of sickness or discomfort in the stomach that may come with an urge to vomit. Nausea is a side effect of some types of cancer therapy.

A bundle of fibers that receives and sends messages between the body and the brain. The messages are sent by chemical and electrical changes in the cells that make up the nerves.

A type of cell that receives and sends messages from the body to the brain and back to the body. The messages are sent by a weak electrical current. Also called neuron.

Not harmful or destructive.

A part of the body that performs a specific function. For example, the heart is an organ.

PDQ is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, complementary and alternative medicine, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information, and more specific information about PDQ, can be found on the NCI's Web site at http://www.cancer.gov/cancertopics/pdq. Also called Physician Data Query.

The main endocrine gland. It produces hormones that control other glands and many body functions, especially growth.

A person who works in a specific profession. For example, a doctor or nurse is a healthcare practitioner.

A molecule made up of amino acids that are needed for the body to function properly. Proteins are the basis of body structures such as skin and hair and of substances such as enzymes, cytokines, and antibodies.

In traditional Chinese medicine, vital energy or life force that keeps a person’s spiritual, emotional, mental, and physical health in balance.

Energy released in the form of particle or electromagnetic waves. Common sources of radiation include radon gas, cosmic rays from outer space, medical x-rays, and energy given off by a radioisotope (unstable form of a chemical element that releases radiation as it breaks down and becomes more stable).

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

A person who has studied science, especially one who is active in a particular field of investigation.

A problem that occurs when treatment affects healthy tissues or organs. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.

Having to do with deep, often religious, feelings and beliefs, including a person’s sense of peace, purpose, connection to others, and beliefs about the meaning of life.

Unable to produce children. Also means free from germs.

A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

A small hollow tube used for injecting or withdrawing liquids. It may be attached to a needle in order to withdraw fluid from the body or inject drugs into the body.

A poison produced by certain animals, plants, or bacteria.

A medical system that has been used for thousands of years to prevent, diagnose, and treat disease. It is based on the belief that qi (the body's vital energy) flows along 20 meridians (channels) throughout the body and keeps a person’s spiritual, emotional, mental, and physical health in balance. Traditional Chinese medicine aims to restore the body’s balance and harmony between the natural opposing forces of yin and yang, which can block qi and cause disease. Traditional Chinese medicine includes acupuncture, diet, herbal therapy, meditation, physical exercise, and massage. Also called Oriental medicine and TCM.

In medicine, a specific event that starts a process or that causes a particular outcome. For example, chemotherapy, painful treatments, or the smells, sounds, and sights that go with them may trigger anxiety and fear in a patient who has cancer. In allergies, exposure to mold, pollen or dust may trigger sneezing, watery eyes, and coughing.

Use of acupuncture to treat pain by inserting needles into trigger points on the body. Trigger points are places on the body where injury has occurred, but the pain has been sent along nerves and is felt in another place in the body.

A nutrient that the body needs in small amounts to function and stay healthy. Sources of vitamins are plant and animal food products and dietary supplements. Some vitamins are made in the human body from food products. Vitamins are either fat-soluble (can dissolve in fats and oils) or water-soluble (can dissolve in water). Excess fat-soluble vitamins are stored in the body’s fatty tissue, but excess water-soluble vitamins are removed in the urine. Examples are vitamin A, vitamin C, and vitamin E.

To eject some or all of the contents of the stomach through the mouth.

In Chinese philosophy, yin and yang are opposite forces that form a whole. Everything contains both yin and yang in a balance that is always changing, such as hot and cold, day and night, and health and disease. In traditional Chinese medicine, disease is diagnosed and treated based on the balance of yin and yang.