For health science papers, a literature review usually spans 10–20% of the article and about 25% in theses, adjusted to journal or program rules.
Readers in medicine, public health, nursing, and allied fields often ask how much space to devote to prior work. The honest answer is: it depends on the document, outlet, and scope. Still, you can set reliable targets, then fine-tune based on journal instructions or departmental handbooks. This guide gives clear ranges, quick math, and editing tips so you can size the section with confidence.
Fast Targets By Paper Type
In most IMRaD articles, the review lives in the opening “Background” inside the introduction. Data drawn from large samples of biomedical papers show that introductions cluster near one-sixth of the total, which matches common practice in health journals. Graduate work treats the review as a stand-alone chapter or a major subsection, so the share rises. Use the table below as a start point, then adjust to fit your venue.
| Context | Word Range For Review | Share Of Total |
|---|---|---|
| Peer-reviewed article (IMRaD) | 400–1,200 words (in Background) | 10–20% |
| Short report / brief | 200–600 words | 8–12% |
| Undergraduate assignment | 500–1,500 words | 15–25% |
| Master’s thesis (health) | 3,000–8,000+ words (chapter) | ~25% |
| Doctoral thesis (health) | 8,000–20,000+ words (chapter) | 20–30% |
| Systematic review article | 800–1,500 words (rationale) | Small share; methods/results dominate |
| Grant protocol | 400–1,000 words | 10–15% |
Why These Ranges Fit Health Writing
Biomedical journals favor concise openings so readers reach methods and results fast. A large analysis of papers in PubMed Central reports a median 14.6% share for the introduction in full-length research articles. That figure supports keeping the review near 10–20% for articles in the health sciences, where the review sits inside the introduction.
Graduate programs in medicine and public health ask for deeper mapping of prior studies. Many faculty guides allot about a quarter of the manuscript to the opening context plus review. One health sciences style guide even splits a thesis into rough shares: ~25% for the introduction and review, ~25% for methods, and the rest for results and interpretation. If your program supplies a template, match it before you start drafting.
Systematic reviews are a special case. The narrative “Background” stays lean, while methods and results carry most of the words due to search strategy, screening flow, risk-of-bias tools, and meta-analytic outputs.
Close Variant: Ideal Length Of The Literature Review In Health Papers
Use a two-step process. First, set a percentage target by document type. Second, run quick calculations from the planned total word count. The next sections walk through both steps with health-specific tips.
Step 1: Pick A Percentage
- Journal article: Aim for 10–20% in the Background. Trend toward the lower end for rapid-communication outlets; the upper end for broad, multi-topic studies.
- Thesis or dissertation: Plan around one-quarter of the whole. In some projects with wide scope, a third is still acceptable if your committee requests more mapping.
- Systematic review: Keep the rationale compact. The heavy lift moves to methods and results.
Step 2: Do The Math
Set the expected total, then apply the target share. A few common cases:
- 3,500-word article: 350–700 words for the review (10–20%).
- 5,000-word article: 500–1,000 words for the review.
- 8,000-word thesis chapter: 2,000 words for a focused review if the program expects 25% at the front.
- 40,000-word doctoral thesis: 8,000–12,000 words for the review chapter.
When To Shrink Or Expand
Shrink The Section If
- The journal’s “Instructions for Authors” sets tight limits.
- Your question builds on a well-trodden line where a handful of sentinel trials frame the topic.
- You can move niche debates to an online supplement.
Expand The Section If
- Your topic spans multiple disciplines (e.g., epidemiology, biostatistics, and implementation science).
- Prior studies diverge in design or results and need careful synthesis.
- You are writing a thesis chapter with a mapping mandate from the program.
Anchor To Real Rules
Always check two sources before you lock a word budget. First, read the reporting guides that fit your study type; for evidence syntheses, the PRISMA 2020 update lays out what belongs where. Second, scan a few recent papers in your target journal to see how much space they give the opening context. For formatting, the APA sample papers page shows how a review-style paper is structured when you write in APA style.
Quick links for reference during planning:
What Editors And Reviewers Expect In Health Fields
Clarity beats volume. A compact, well-sourced map of prior work earns trust and keeps readers moving. Editors look for three things:
- Relevance: Cite up-to-date trials, surveillance reports, and core methods papers.
- Synthesis: Group studies by design or theme. Summarize points of agreement and any tension in the findings.
- Lead-in to your aim: End with the specific gap your study will answer. One tight paragraph is enough.
Common Length Mistakes In Health Manuscripts
Too Short
Readers lose the thread when context is just a string of citations. Aim for a narrative that explains the state of evidence, not a list.
Too Long
Walls of background crowd out methods and results. Trim history and side paths that do not change your question or design.
Unbalanced Citations
Mix randomized trials, observational studies, and core reviews where relevant. Over-weighting any one type can skew the take-home.
Sizing Guide For Health Projects
Use this quick calculator to translate totals into target ranges across common health science documents.
| Total Word Count | Article Background (10–20%) | Thesis Review (≈25%) |
|---|---|---|
| 3,000 | 300–600 | ~750 |
| 4,000 | 400–800 | ~1,000 |
| 5,000 | 500–1,000 | ~1,250 |
| 6,000 | 600–1,200 | ~1,500 |
| 8,000 | 800–1,600 | ~2,000 |
| 10,000 | 1,000–2,000 | ~2,500 |
| 40,000 | 4,000–8,000 | ~10,000 |
Workflow To Hit The Target
Plan
- Draft an outline with 3–5 thematic subheads.
- Set a citation plan (e.g., sentinel trials, meta-analyses, surveillance data).
- Allocate words to each subhead up front.
Draft
- Lead with the clinical or population problem.
- Move from broad to specific themes.
- End with the precise gap and study aim.
Edit
- Cut repeats and side stories.
- Swap long quotes for short paraphrases with citations.
- Merge tiny paragraphs into lean, readable blocks.
Field-Specific Notes
Clinical Trials
Point to prior phase data and any safety signals that shape dosing and outcomes. Keep brand names to a minimum unless required for clarity.
Epidemiology
Show the time frame, population, and case definitions used across studies so readers can align results at a glance.
Health Services
Flag study designs that carry typical biases in this area, such as selection in administrative datasets, and cite methods papers that tackle them.
Final Checks Before Submission
- Match the journal or program template.
- Scan two recent papers or theses from your venue and mirror their section balance.
- Run a word count and confirm the review sits inside the target band.
- Ensure citations include recent, high-quality sources.
Key Takeaway For Health Authors
Use 10–20% of the manuscript for the review in articles and around one-quarter in theses. Tie the size to venue rules, keep the narrative tight, and guide the reader straight to your aim. That balance serves both busy clinicians and markers.