1.4 Combining Forms – The Language of Medical Terminology (2024)

An electroencephalogram (EEG) is a common diagnostic test that looks at the electrical activity of the brain. This term means “to record” (-gram) “electricity” (electr/o) in the “brain” (encephal/o). Fig. 1.3 shows a patient getting an electroencephalogram.

Fig. 1.4 is an image of several different types of blood cells. The larger disc-shaped ones are erythrocytes (red blood cells), the round, fuzzy cells are leukocytes (white blood cells), and the tiny disc-shaped cells are thrombocytes (platelets). The term erythrocyte comes from the suffix -cyte, meaning “cell,” and the combining form erythr/o, meaning “red.” Literally, it means “cell that is red” or, more commonly, “red blood cell.”

Fig. 1.6 is an image of an ophthalmoscope, an instrument used to view and assess the eye. The term means an “instrument” (­scope) to view the “eye” (ophthalm/o). In this term, you keep the combining vowel because the suffix starts with a consonant.

Also, notice the combining form nat/i, meaning “birth,” in the table above. It is one of the few combining forms where the vowel is an i,not an o.

The combining form ur/o means “urine” or “urea.” In the term uremia, ur/o means “urea.” This term means “blood condition” (-emia) with “urea” (ur-). Urea is a waste product in blood that builds up when the kidneys are not functioning properly (Betts et al., 2013).

The term uremia often gets confused with the term hematuria; however, hematuria means “a condition of urine” (-uria) with “blood” (hemat-) (Ansorge, 2022).

Fig. 1.8 is an image of inflamed tonsils, or tonsillitis. This term means “inflammation” (-itis) of the “tonsils” (tonsill/o).

Fig. 1.9 is an image of a tracheostomy. This term means an “opening” (-stomy) into the “trachea” (trache/o). There are a number of medical conditions that require a patient to have a tracheostomy, including major burns, long-term comas, and certain types of tumours (John Hopkins Medicine, 2022b).