Glossary

Health Terms beginning with "M"

Macrosomia

Literally means "large body" and is used in fetal medicine to refer to babies with a birth weight greater than eight pounds and 13 ounces. Maternal diabetes is the strongest risk factor for fetal macrosomia, which can cause complications in delivery.

Macula

Central part of the retina of that allows you to see fine, sharp details straight ahead.

Macular degeneration

The general term for eye diseases in which the central part of the light-sensitive tissue in the eye that sends visual messages to brain is destroyed.

Magnetic resonance angiography (MRA)

An imaging technique using the iron in the hemoglobin of the red blood cells to create an image of the flowing blood through the vessel; often used to detect stenosis of the brain arteries inside the skull.

Magnetic resonance imaging (MRI)

The patient is safely surrounded by a magnetic field through which pulses of radio frequency radiation are projected. The test can show differences in tissue and bone structure and help identify masses. The test carries little risk and can be performed during pregnancy. However, it cannot be used on pateints who have metal in their body, such as metal clips or plates, or a pacemaker. Some patients complain of claustrophobia during the test, but a mild sedative may help. This can be performed on an outpatient basis.

Major depression

Clinical depression. Also called unipolar disorder.

Malaria

A human disease caused by parasites in the red blood cells that is transmitted by the bite of certain mosquitoes and is characterized by periodic attacks of chills and fever.

Maldynia

Constant pain that lasts for at least three months or indefinitely. May not have an obvious cause and may be disabling, affecting daily life. Maldynia can cause fatigue, concentration problems and appetite changes and lead to suppression of the immune system, depression, anxiety and even suicide.

Malignant

Cancerous.

Malignant Tumor

A tumor made up of cancer cells of the type that can spread to other parts of the body.

Mammogram

X-ray screening for diagnosis of breast problems, including cancer.

Mania

A mental disorder characterized by extreme excitement, happiness, overactivity and agitation; usually refers to the extreme irritability or elation, or highest peak in the spectrum of emotion and behaviors associated with bipolar disease (also called manic depressive disorder).

Manic depression

A mental health disease characterized by cyclic periods of depression followed by cycles of euphoria. This should be ruled out when diagnosing PMS. Women are not at higher risk than men for bipolar illness.

Manic depressive illness (also called bipolar disorder)

A mental health disease characterized by cyclic periods of depression followed by cycles of euphoria. This should be ruled out when diagnosing PMS. Women are not at higher risk than men for bipolar illness.

Manipulation

As part of chiropractic care, a joint is forced beyond its existing range of motion to increase its mobility/functionality; often accompanied by an audible pop or click. As part of osteopathic medicine, manipulation means, simply, therapeutic application of manual pressure or force to the soft tissues of the spine.

MAO inhibitor

An antidepressant drug also used to treat migraines. It blocks an enzyme called monoamine oxidase, which normally helps nerve cells absorb the artery-constricting chemical, serotonin.

Martial art

Techniques (developed in the East) designed to enhance mental, spiritual and physical health through intense physical activity; often refers to any of various forms of self-defense (usually weaponless) based on these techniques.

Massage

Therapeutic massage soothes aching muscles, stimulates blood circulation and promotes a sense of well being. Self-massage is an excellent way to relieve tension in the neck.

Mastectomy

Surgical removal of one or both breasts to remove breast cancer.

Mastopexy

A surgical procedure to lift the breasts and reduce sagging and drooping.

Maternal serum screening

Certain tests can be performed using your blood to detect substances from the fetus that could be a sign of a birth defect. All pregnant women are usually offered this test, which typically occurs between weeks 15 and 18 of your pregnancy. One of the more common substances tested is alpha-fetoprotein (AFP). If high levels of AFP show up, it could be a sign of a neural tube defect (such as spina bifida), which results when the brain or spinal cord doesn't develop normally. Low levels of AFP could be a sign of Down syndrome.

Maudsley model

An innovative family-centered treatment program for eating disorders where the family assumes responsibility for making the patient eat. No one is "blamed" for triggering the illness; rather, the eating disorder is treated as a medical condition and the family taught to care for the sick child. The power shifts back to the patient after he/she reaches an acceptable weight.

Maxillary sinuses

The sinuses inside your cheekbones. If these sinuses are infected, your jaw and your teeth might hurt, and your cheeks might be tender.

Mediastinoscopy

A surgical procedure in which a small cut is made in your neck and a hollow lighted tube is inserted behind the sternum (breastbone). Special instruments inserted through this tube take tissue samples from the mediastinal lymph nodes, as well as the windpipe and major bronchial tube areas. Looking at the samples under a microscope can show whether cancer cells are present and help make a definitive cancer diagnosis.

Mediastinotomy

A surgical procedure that removes samples of mediastinal lymph nodes while the patient is under general anesthesia in order to look for lung cancer. The surgeon opens the chest cavity by making a small incision beside the sternum, enabling the surgeon to reach lymph nodes not reached by standard mediastinoscopy.

Medicaid

A joint federal and state program that helps pay medical costs for those with limited resources.

Medical power of attorney

Also called a durable power of attorney for health care, health care proxy or appointment of health care agent, this is a type of advance directive that allows you to name someone you trust to make medical decisions for you in the event you are unable to make them on your own. Unless you formally appoint someone, many health care providers and institutions will make critical decisions for you that might not be based on your wishes. In some situations, a court may have to appoint a guardian unless you have already done so.

Medicare

A federal health-insurance program administered by the Health Care Financing Administration; generally for those 65 years or older.

Meditation

A state of consciousness in which you try to stop awareness of surroundings so the mind can focus on a single thing such as a sound or image; leads to a state of rest and relief from stress.

Medullary carcinoma

A well-confined cancer that also appears in the ducts. It accounts for 7 percent of all breast cancers.

Meibomian glands

Glands in the lower eyelid area that produce the oily outer layer of tears.

Melanin

Skin pigment.

Melanocytes

The skin cells that produce melanin.

Melanoma

The most severe form of skin cancer, often originating in a mole.

Melatonin

A naturally occurring hormone, melatonin is sold over the counter in pill form to treat sleeplessness; it is a supplement and therefore not regulated by the FDA.

Meningitis

An infection of the meninges, or the lining of the brain.

Menopause

When a woman's monthly menstrual periods end permanently, signifying the end of her childbearing years. Although the average age for menopause in the United States is 51, some women experience menopause earlier due to natural causes or following surgery, illness or other treatments that lessen ovarian function. Menopause is said to have occurred when a woman has not had a menstrual period for 12 months.

Menorrhagia

Prolonged or profuse uterine bleeding. Normal menstrual periods usually last four or five days, but if you have fibroids, your periods are likely to last longer than seven days.

Menstrual cycle

Also called a period. A monthly process in which your body sheds the lining of the uterus. The buildup of tissue, blood and fluids is necessary to help prepare the uterus to support a pregnancy. When pregnancy doesn't occur, the body expels these substances and immediately starts making a new lining. It might be a year or more after your first period before your period comes regularly every month.

Menstrual migraine

Headaches that occur around the time of the menstrual period. They may disappear during pregnancy, but some women develop migraine for the first time when pregnant. Some are first affected after menopause.

Mental health counselor

Provides professional counseling services that involve psychotherapy, human development, learning therapy and group dynamics.

Meridians

In traditional Chinese medicine, the main pathways throughout the body for the flow of chi, or vital energy.

Metabolic syndrome

A group of risk factors present in an individual related to obesity. Factors are central obesity, high triglycerides and low HDL cholesterol, high blood pressure, insulin resistance or glucose intolerance and several other conditions, called proinflammatory and prothrombotic states.

Metabolism

The method by which your body processes food into energy and then uses that energy.

Metastasis

The spread of a cancer from one part of the body to another. Cells in the metastatic tumor (the second tumor) are like those in the original tumor.

Metastasize

The process by which cancer cells spread from their original localized area to other parts of the body.

Methamphetamine hydrochloride

A central nervous system stimulant sometimes prescribed for narcolepsy.

Methotrexate

This folic acid inhibitor suppresses the immune system and is commonly prescribed for rheumatoid arthritis. It can also be used to treat patients who have Sjögren's syndrome with internal organ involvement. Side effects include upset stomach, potential liver problems and low white blood cell count.

Methylphenidate hydrochloride

A central nervous system stimulant sometimes prescribed for narcolepsy.

Methyltestosterone

An oral form of testosterone.

Methysergide maleate

A drug used to prevent migraines with or without aura. It counteracts blood vessel constriction.

Miconazole

An antifungal medication available in some over-the-counter preparations to treat vaginal yeast infections.

Micromastia

Very small breasts.

Micronized natural progesterone

Progesterone derived from yams and formulated into a pill containing micronized (micron-length) particles. This product (marketed under the brand name Prometrium) is better absorbed than other natural progesterones.

Microwaves

Microwave therapy is a type of deep heat therapy. The electromagnetic waves pass between electrodes placed on your skin to create heat that increases blood flow and relieves muscle and joint pain.

Migraine

A maldynia condition caused by a biologically based disorder whose symptoms are the result of changes in the brain. Lasting from two to six hours, migraines are accompanied by throbbing pain, nausea, visual symptoms, such as flashing lights, zigzag lines or partial loss of vision and sensitivity to sound and smells.

Migraine with aura

A migraine with aura is preceded by neurological symptoms (called an aura) 10 to 30 minutes before the attack. You may see flashing lights or zigzag lines or may temporarily lose vision. Other classic symptoms include speech difficulty, weakness of an arm or leg, tingling of the face or hands and confusion. The pain of a migraine with aura is described as intense, throbbing or pounding and is felt in the forehead, temple, ear, jaw or around the eye. Migraine with aura starts on one side of the head but may eventually spread to the other side. An attack lasts one to two days.

Migraine without aura

This migraine is not preceded by an aura. Some people experience a variety of vague symptoms beforehand, including mental fuzziness, mood changes, fatigue and unusual retention of fluids. During the headache phase of a migraine without aura, a person may have diarrhea and increased urination, as well as nausea and vomiting. Migraine without aura pain can last three or four days.

Mild depression

When some symptoms of depression are present requiring the patient to give extra effort to accomplish responsibilities.

Milligram (mg)

A unit of weight equal to one-thousandth of a gram. There are about 28,350 mg in one ounce. Dietary cholesterol is measured in milligrams.

Milligrams/Deciliter (mg/dL)

The measure used to express cholesterol and triglyceride levels in the blood. It stands for the weight of cholesterol in milligrams in a deciliter of blood. A deciliter is one-tenth of a liter or about one-tenth of a quart.

Mini-pill

Similar to combined oral contraceptive pills, but they contain no estrogen. They must be taken every day. While not as effective as combined oral contraceptives, they can be used by women who can't tolerate estrogen or those who are breastfeeding.

Miotics

A class of drugs in drop, gel and insert form used to treat glaucoma by increasing the rate at which the aqueous humor flows out of the eye.

Miscarriage

Also known as a spontaneous abortion, it's the loss of your pregnancy before the fetus is developed enough to survive on its own (20 weeks gestation). It occurs in about 15 percent of all pregnancies. It usually happens in the first trimester, or first 12 weeks of pregnancy. After four months, it's much less likely to occur. However, the risk of miscarriage increases with age.

Mixed incontinence

A combination of types of incontinence, usually stress and urge.

Mixed state

Symptoms of mania and depression are present at the same time and usually include agitation, trouble sleeping, significant change in appetite, psychosis and suicidal thinking.

Mixer

A type of chiropractor who uses various treatments—including traditional medical, alternative and/or holistic methods—in addition to manual manipulation of the spine and the rest of the musculoskeletal system, which comprises 60 percent of the body's systems.

Modeling treatment

A behavioral therapy in which the patient observes an actor confronting the object of fear and reacting in an appropriate way.

Moderate depression

Most symptoms of depression are present and often prevent a person from accomplishing things he/she needs to do.

Modified radical mastectomy

Breast cancer surgery that removes the entire breast along with the underarm lymph nodes.

Mold

One of the two groups of plants in the fungus family (yeast is the other). Molds consist of many cells that grow as branching threads. The seeds, called spores, are easily carried by air currents. When inhaled, the spores, or sometimes mold fragments themselves, can cause allergic reactions. Molds thrive in warm, most places. The mold season often peaks from July to late summer but can thrive year-round indoors.

Monoamine oxidase inhibitors

Anti-depressants thought to regulate chemicals in the central nervous system; they should rarely be the first medication used, because they may interact dangerously with many other medications, foods and beverages.

Monogamy

The practice of having sex with only one partner.

Mononucleosis

An acute infectious disease associated with Epstein-Barr virus and characterized by fever and swelling of lymph nodes.

Monosodium glutamate (MSG)

A flavor enhancer added to some foods. When consumed in large amounts, MSG can cause flushing, sensations of warmth, headache, facial pressure and chest pain in some people. This is an example of a food intolerance and not a true food allergy.

Monounsaturated fat

Unsaturated fat that is found in greatest amount in food from plants, including olive oil and canola oil.

Morphea

A type of localized scleroderma in which oval patches of inflamed and discolored skin may appear on the body. Many morphea patients will improve spontaneously over time.

Motility

The contraction of intestinal muscles and movement of its contents. Motility is controlled by nerves and hormones.

Moxibustion

A type of acupuncture in which dried herbs are placed on top of acupuncture needles or directly on/over the skin and burned.

Mucin

The inner layer of tears closest to the eye that spreads the watery layer of tears across the eye and keeps the eye wet.

Mucinous carcinoma

A ductal carcinoma, contains mucus-producing cells which make the tumor glisten. It accounts for only 3 percent of all cases.

Mucociliary disturbances

Sometimes a cause of chronic sinusitis, this refers to problems with the movement of mucus.

Multiple sclerosis

Greek for "many scars." MS is an autoimmune disease whose cause is unknown. It is a disease of the central nervous system in which the transmission of electrochemical messages is slowed or even halted, resulting in impaired functions.

Multiple sleep latency test (MSLT)

A diagnostic test for narcolepsy and sleep apnea that is primarily used as a means of quantifying sleepiness. During this test you are given a chance to sleep every two hours during normal wake times; observations are made of the time taken to reach various stages of sleep to measure the degree of daytime sleepiness and how soon rapid-eye-movement sleep begins.

Multiple sub-pial transection

A type of operation in which surgeons make a series of cuts in the brain that are designed to prevent seizures from spreading into other parts of the brain while leaving the person's normal abilities intact.

Muscle contraction headaches

Appear to involve the tightening or tensing of facial and neck muscles.

Musculoskeletal system

Refers to your body's tendons, muscles, ligaments, joints and bones.

Mutation

A change in the structure of DNA, often originating from environmental damage, such as ultraviolet radiation from the sun or exposure to chemicals. A mutation may have no effect, may cause harm or may (rarely) prove beneficial (evolution is accomplished through replication of advantageous mutations). A gene with a mutation may be rendered non-functional or may produce an abnormal version of the protein for which it encodes. Because genes are paired, we have some built-in protection from mutations—often the non-mutated gene overrides the effects of a mutated one.

Mycoplasma

A sexually transmitted micro-organism that can cause urinary tact infection.

Myelin

Fatty material that covers and insulates nerve cell fibers in the brain and spinal cord. Myelin eases the fast, smooth transmission of messages between the brain, spinal cord and the rest of the body. When myelin is damaged, nerve fiber conduction is faulty or absent and impairs bodily functions. These demyelinated nerve fibers are identified as symptoms of MS.

Myoclonic seizures

Seizures that cause sudden jerks or twitches, especially in the upper body, arms, or legs.

Myolysis

An innovative laparoscopic procedure that uses an electrical needle to destroy the small blood vessels feeding a fibroid. The procedure is most effective in treating relatively small fibroids near the surface of the uterus.

Myomectomy

This surgical procedure removes fibroids, leaving the uterus intact, which can preserve fertility. The procedure is performed either through an open incision in the abdomen or by electrosurgical resection.

Myopia

Nearsightedness, or being able to clearly see objects close up but not far away.