1. Use a semicolon to separate two independent clauses that are not joined by a conjunction such as and, but, for, or, nor, but are related in meaning. In the following example,the semicolon takes the place of a period.
Lungs are clear to auscultation; no rales or rhonchi are present.
2. If the word however or therefore separates two independent clauses, place a semicolon before the word and a comma after it.
The patient was very tired; however, he did not complain of weakness.
Dr. Campbell reported that the pathology specimen was negative; therefore, no further follow-up is necessary.
3. Use a semicolon to separate main sections when the separate internal elements are already separated by commas.
Heart: Regular rate and rhythm; no murmur, gallop, or rub; Sl and S2 normal.