Paragraphs and examples

A paragraph develops one connected idea through sentences arranged for a purpose. Its opening, supporting detail, examples and ending help the reader follow that idea; a break signals a change of topic, focus or emphasis.

Purpose and unity

A paragraph is a collection of sentences relating to a common theme, like a small essay. ¹ Paragraphing groups sentences into manageable, logical chunks to make text understandable and help tell its story. ^{2, 3, 4, 5} It acts as macropunctuation: where punctuation divides words within a sentence, paragraphing groups sentences and places logical breaks between them. ⁶ A break gives readers a pause to consider the preceding material and signals a possible shift of focus. ⁵

Paragraphing depends on the document and audience rather than a single set of standard rules. ² Reviewers, patients and physicians can expect different treatment in a scientific paper, Clinical Overview, package leaflet, Periodic Safety Update Report or patient information booklet. ² Highly structured regulatory documents leave less room for conventional paragraph development than scientific papers, and different sections of one document may need different treatment. ²

The word derives from “para-”, beside, and “graphein”, to write; the ancient Greek paragraphos was a gamma-derived mark indicating a division in text, such as a change of speaker. ⁷

Context, content and conclusion

A common paragraph structure has three parts, sometimes called the three C's: context, content and conclusion. ^{1, 8, 9}

1. State the topic or main idea early, setting the scene and the limits of the paragraph.
2. Develop that idea with supporting details, concrete examples, relevant arguments, pros and cons.
3. Conclude meaningfully, perhaps returning to the opening idea or leading into the next paragraph.

^{1, 8, 9}

The content should remain within the limits set by the topic and conclusion. ⁸ A topic can be expressed as a message or question, and a concluding summary is optional where it does not serve the paragraph's purpose. ¹⁰

Topic sentences

Biomedical paragraphs usually put the main idea first, followed by supporting data, information or examples in a logical order. ^{3, 11} Putting the main idea first helps readers skim for an overview before concentrating on a particular paragraph. ¹¹ The topic sentence should have a simple structure, with its subject close to its verb. ¹¹ Reading successive opening topic sentences alone should reveal the progression of the argument. ¹² Putting a conclusion before its supporting details is also called deductive writing. ¹³

A topic sentence can occupy three positions. ¹⁴

• At the beginning, it sets the scene and defines the content, sometimes taking up an idea from the previous paragraph.
• In the middle, it gathers and redirects the content, a device used in creative writing but rare in medical and scientific documents.
• At the end, it summarises the content and may introduce what follows.

¹⁴

In flowing prose, readers should not have to reach the middle or end before discovering the paragraph's subject. ¹⁴ For example, a paragraph describing concurrent vaccine administration and a second aim concerning a two-dose schedule becomes easier to follow when it opens “The present study had two aims. The primary aim was … The secondary aim was to assess …”. ¹⁴ A buried conclusion can move to the front as a topic sentence, while a long enumeration can become a list. ¹⁵ “One of our findings was surprising” is a weaker opening because it promises a finding without identifying it; naming the finding first establishes what the supporting explanation concerns. ¹⁴

A topic sentence is not indispensable to every well-written paragraph: the paragraph's purpose, logical order and shifts of focus can determine its structure. ¹⁶ In regulatory documents, section headings may already identify the subject, making another topic sentence unnecessary. ¹⁴

From an outline to a paragraph

Main points in an outline can become topic sentences, helping each paragraph keep one idea and maintain the storyline. ^{17, 4, 18, 19} Beneath a main point, two or three supporting sentences might provide a transition, an example or a comparison; two to five supporting subpoints is a suggested drafting range. ²⁰ Joining the related points develops the paragraph, and a second main idea calls for a new paragraph. ^{21, 22}

A paragraph can begin with general knowledge or the preceding text, develop new information and end when another information block needs its own paragraph. ²³ Planning the hierarchy of the main idea and subtopics helps organise the sequence. ²³

Structure that follows the paragraph's purpose

A narrative paragraph may have equally important event sentences without a separate topic sentence; breaks can mark natural pauses, changes in action, setting or perspective. ²⁴

Instructions generally follow the order of the actions and can use paragraph breaks for major steps, such as anaesthesia options, patient positioning and an initial incision. ²⁵ A recipe can refer to a separate preliminary procedure, such as making sourdough starter, so its overall timeline need not be strictly linear. ²⁵

An explanatory paragraph may define its subject and add detail, with a new paragraph marking a change of emphasis rather than a wholly new topic. ²⁶ For example, a break can separate insulin secretion from insulin's effects without repeating a topic sentence, while a subsequent change to glucagon introduces a new topic and may justify a heading. ²⁶

A paragraph describing a whole and its parts can name the parts in its topic sentence and develop each in parallel sentences; a bulleted list may make a long sequence easier to digest. ²⁷

Ordering the supporting sentences

Sentences can follow chronology, rank of importance, reverse rank or a simple list when there is no reason for a stronger sequence. ²⁸ Logical ordering makes the passage easier to read. ²⁹ A chronological account can use introductory dates and time expressions such as “began”, “since”, “in 2011” and “now” to lead through the sequence. ³⁰ Common biomedical story structures move from old to new information, least to most important, for to against, or problem to solution. ³¹

A paragraph can also explain a mechanism before the consequences it helps make understandable. ³² In a paragraph on Parkinson's disease, moving the description of neuronal changes after the introductory definition and before the symptoms makes that relationship clearer; the sentence on treatment closes the paragraph. ³²

An argumentative paragraph can state its claim near the beginning or end, define necessary terms, give supporting evidence and explain why the evidence justifies the claim. ³³ A break should not leave a phrase such as “all of this evidence” with an uncertain reference; moving the claim earlier and then supplying the evidence may solve the problem. ³³ When a topic sentence promises A and B, the supporting explanation should address A and then B. ³⁴

Examples that explain a general statement

Concrete examples clarify general statements and bring writing to life, while unsupported general assertions need scrutiny. ³⁵ Medical data such as laboratory tests, drugs and doses, or descriptions of cases, can supply that specificity. ³⁵

A general statement about the primary-care physician's role becomes concrete through a particular diagnostic distinction. ^{36, 37}

• General statement: “The primary care physician must be the expert in the care of common illnesses and in the recognition of uncommon diseases.”
• Example: “The general internist or family physician should be skilled in the management of degenerative joint disease and be able to differentiate it from rheumatoid arthritis, intraarticular infection, gout, and other causes of joint pain.”

^{36, 37}

A second pair shows how an example supports a statement about changing medical knowledge. ^{38, 39}

• General statement: “Sometimes we find that drugs once avoided in certain diseases actually can be helpful.”
• Example: beta-blockers were once avoided in congestive heart failure but proved useful for some patients with heart failure.

^{38, 39}

The order can be reversed to gain attention: an illustrative case begins with a public-assistance patient who stops an H2-blocker after it becomes available over the counter, then explains the general point about unintended effects of access policies. ¹ In the case, prescription coverage previously paid for the medicine, whereas the over-the-counter version required the patient to pay, reducing its use despite increased availability. ¹

An analogy can help explain a complex concept, as when a mitochondrion is described as the cell's powerhouse. ⁴⁰

Reviewing a draft paragraph

Highlighting the main statement in one colour and its supporting examples in another reveals their position and relationship; the main statement should generally precede its support unless an example is deliberately used first to attract attention. ²⁸

Four editing questions examine the paragraph's opening, development and ending. ⁴⁰

1. Does the first sentence describe the main idea?
2. Do the following sentences expand on that idea and add information?
3. Is the paragraph well researched and referenced?
4. Does the last sentence summarise the main idea or lead to the next paragraph?

⁴⁰

A second review examines completeness, relevance and order. ⁴¹

1. Is all the information needed to make the point present, including definitions of unfamiliar words?
2. Should irrelevant sentences move to another paragraph or be deleted?
3. Would a different sentence order make the paragraph clearer?
4. Are the paragraphs in the right order for the piece as a whole?

⁴¹

Two subjects may require two paragraphs rather than a stronger opening alone: discussion of a treatment's usefulness and uncertain effect on outcomes can be separated from discussion of its delays and toxicity. ⁴² Each paragraph can then receive its own topic sentence, with any necessary qualification from the original opening incorporated into it. ⁴²

In a draft on herpes zoster, a topic sentence naming it as common, painful and mostly affecting adults over 50 establishes the three aspects the paragraph develops. ⁴³

Consistent naming can clarify a paragraph whose terms appear to designate different subjects. ⁴⁴ In a chemotherapy draft, defining “cutaneous reactions” as the subject brings together “side effects”, “skin reactions” and “cutaneous reactions”, while a separate paragraph addresses skin-barrier function. ⁴⁴

Length and emphasis

A paragraph is a unit of thought rather than a fixed length: it should be homogeneous in subject and sequential in treatment. ⁴⁵ One subject may need several paragraphs if its treatment becomes unreasonably long, but unrelated passages should not be combined merely because each is short. ⁴⁵ A succession of very short paragraphs can irritate readers, while very long ones can be wearisome. ^{45, 46}

A paragraph exceeding eight or ten sentences should be checked for a logical place to divide it, and a paragraph covering several topics almost certainly needs division. ⁴⁶ For study-report-type text, a suggested page-level aim is roughly two or three paragraphs per page; a paragraph running beyond a page should be avoided as off-putting. ⁴⁵ Another visual-writing recommendation is that paragraphs should typically occupy no more than six to eight lines, creating white space and manageable pieces. ⁴⁷

A screen-based rule of thumb regards a paragraph that cannot be seen all at once as probably too long and recommends looking for a reasonable break. ⁴⁸

Journal manuscripts should be checked again at proof stage, when a two-column layout may require some reparagraphing, usually limited. ⁴⁵ Marketing, medical-communications and website copy allow more freedom than regulatory documents, manuscripts and textbooks. ⁴⁵

A single-sentence paragraph can deliberately emphasise a point, but frequent use can overemphasise content and irritate readers. ^{46, 49} Such paragraphs may suit some regulatory sections, marketing and medical-communications text, an opening paragraph or a concluding paragraph at the end of a Discussion. ^{49, 50} In journal articles and product monographs they should generally be avoided unless the emphasis is wanted; otherwise the surrounding paragraphs should be revised. ⁴⁹

Breaking every sentence into its own spaced paragraph can make web copy disjointed rather than encourage continued reading. ⁵¹