Glossary of Medical Terms

A substance that breaks up into ions (particles with electrical charges) when it is dissolved in water or body fluids. Some examples of ions are sodium, potassium, calcium, chloride, and phosphate. These ions help move nutrients into cells, help move waste out of cells, and help nerves, muscles, the heart, and the brain work the way they should.

An area of electric and magnetic forces caused by electromagnetic radiation. Researchers are studying whether the electromagnetic fields from power lines, electrical appliances, and wireless and cellular telephones can cause cancer or other harmful health effects. Also called EMF.

Radiation that has both electric and magnetic fields and travels in waves. It comes from natural and man-made sources. Electromagnetic radiation can vary in strength from low energy to high energy. It includes radio waves, microwaves, infrared light, visible light, ultraviolet light, x-rays, and gamma rays. Also called EMR.

The complete range of all types of radiation that has both electric and magnetic fields and travels in waves. The electromagnetic spectrum ranges from low-energy, low-frequency radiation that travels in long waves (such as radio waves and microwaves) to high-energy, high-frequency radiation that travels in short waves (such as x-rays and gamma rays).

A small particle with a negative charge that is found in all atoms. Streams of electrons made by special equipment can be used for radiation treatment.

A stream of electrons (small negatively charged particles found in atoms) that can be used for radiation therapy.

A microscope (device used to magnify small objects) that uses electrons (instead of light) to produce an enlarged image. An electron microscope shows tiny details better than any other type of microscope.

A device that has the shape of a cigarette, cigar, or pen and does not contain tobacco. It uses a battery and contains a solution of nicotine, flavorings, and other chemicals, some of which may be harmful. When electronic cigarettes are used, the nicotine solution turns into a mist that can be inhaled into the lungs. The amount of nicotine in individual e-cigarettes can vary. It is not yet known whether electronic cigarettes are safe or if they can be used to help smokers quit smoking. Also called e-cigarette.

An electronic (digital) collection of medical information about a person that is stored on a computer. An electronic health record includes information about a patient’s health history, such as diagnoses, medicines, tests, allergies, immunizations, and treatment plans. Electronic health records can be seen by all healthcare providers who are taking care of a patient and can be used by them to help make recommendations about the patient’s care. Also called EHR and electronic medical record.

An electronic (digital) collection of medical information about a person that is stored on a computer. An electronic medical record includes information about a patient’s health history, such as diagnoses, medicines, tests, allergies, immunizations, and treatment plans. Electronic medical records can be seen by all healthcare providers who are taking care of a patient and can be used by them to help make recommendations about the patient’s care. Also called EHR and electronic health record.