Don’t let the title scare you – these are some of the easiest, least intimidating diagnostic tests you can have. They’re commonly used because they’re noninvasive (no poking or prodding needed!) and they can give a lot of information about the heart or the brain. They may sound similar, but one of these things is not like the other: both ECG and EKG refer to a test of the heart, while EEG is a test of the brain.
Electrocardiogram (ECG or EKG) is a painless test that measures the electrical activity in the heart. The EKG provides two important pieces of information: the time intervals on the EKG measure how long it takes each electrical wave to pass through the heart, which alerts the doctor to an irregular, fast, or slow heartbeat. The EKG also reveals the amount of electrical activity passing through the muscle of the heart itself, which can reveal any enlargement or overworking of the heart.
Wait, there’s no K in electrocardiogram. Why is it sometimes called EKG?
Electrocardiography was invented in 1903 by Dutch Nobel Laureate Willem Einthoven, who, it should be noted, spelled electrocardiogram with a C. However, when he translated his work into German, it became elektrokardiogramm, which is the origin of the abbreviation EKG. EKG is commonly used in the United States, but most of the English-speaking world uses ECG.
Electroencephalogram (EEG) is a test that measures electrical impulses in your brain through little metal discs called electrodes stuck to your scalp. Don’t worry – the electrodes only measure electrical activity coming out of your brain, they don’t create any sensation and the test is completely painless.
The electrical signals in your brain, or brain waves, are recorded in peaks and valleys on the graph. Lots of rapid spikes can indicate a seizure or epilepsy, while very slow brain waves can suggest a tumor or a stroke. EEG is also used to detect head injuries, sleep disorders, dementia or Alzheimer’s Disease, and more.