At the A1 level, you can think of **急増 (kyūzō)** as a way to say 'increased very fast'. You already know 'fueru' (to increase). 'Kyūzō' is just a more 'grown-up' or 'news-like' way to say that something became a lot more in a short time. You might see it in simple news for students or on posters. For example, 'The number of people using this park has increased rapidly.' It's a combination of 'Sudden' (Kyū) and 'Increase' (Zō). Even if you can't write the kanji yet, remembering the sound 'kyūzō' will help you understand when Japanese people are talking about a big change in numbers. It's often used with things like 'tourists', 'users', or 'orders'.
At the A2 level, you should start using **急増 (kyūzō)** as a suru-verb. Instead of just saying 'takusan ni narimashita' (became a lot), you can say 'kyūzō shimashita'. This makes your Japanese sound more precise. You will often use the particle 'ga' with it. For example: 'Riyōsha ga kyūzō shite imasu' (Users are increasing rapidly). This level is about recognizing the word in contexts like weather reports (e.g., rapid increase in heatstroke cases) or local news. It's a great word to use when you want to describe a trend you've noticed, like more people wearing a certain fashion or more people visiting a specific cafe.
At the B1 level, you should be comfortable using **急増 (kyūzō)** in both spoken and written forms, especially in work or academic settings. You should understand that it is a formal word (kango) and is preferred over 'kyū ni fueru' in reports. You'll start to see it in compound phrases like 'demand surge' (juyō no kyūzō). At this level, you should also be able to distinguish it from 'zōka' (general increase). You might use it to explain social trends in Japan, such as the rapid increase in foreign workers or the rapid increase in single-person households. It's a key word for passing the JLPT N3 level.
At the B2 level, **急増 (kyūzō)** becomes a tool for analysis. You don't just use it to state a fact; you use it to introduce a problem or a cause. For example, 'The rapid increase in e-commerce has led to a shortage of delivery drivers.' You should also be able to use its synonyms like 'gekizō' (extreme increase) or 'kyūtō' (price surge) to add nuance to your descriptions. You'll encounter this word in editorials and business journals. You should also be aware of the passive-like nuances—while 'kyūzō' is intransitive, the 'cause' of the increase is often discussed using 'ni yoru' (due to).
At the C1 level, you use **急増 (kyūzō)** with high precision in complex sentences. You understand its sociological and economic implications. You can discuss the 'kyūzō' of speculative investments or the 'kyūzō' of social media misinformation with ease. You also recognize the word in high-level literature and technical white papers. At this level, you are expected to know the kanji perfectly and be able to use the word in formal presentations without hesitation. You might also use it metaphorically or in highly specific technical contexts, such as 'a rapid increase in data traffic' in a networking context.
At the C2 level, **急増 (kyūzō)** is part of a vast repertoire of vocabulary used to describe fluctuations. You can differentiate between 'kyūzō', 'shinchō' (extension/growth), 'kodai' (expansion), and 'hōshatsu' (radiation/spread) with native-like accuracy. You understand the historical context of the word and can use it in high-stakes environments like policy-making or academic research. You might use it to describe the 'exponential' nature of a trend, often pairing it with adverbs like 'shisū-kansū-teki ni' (exponentially). Your usage is flawless, and you can manipulate the word's register to suit any audience, from a casual blog post to a formal legal document.

急増 in 30 Seconds

  • 急増 (kyūzō) means a rapid or sudden increase.
  • It is a combination of 'sudden' (急) and 'increase' (増).
  • Commonly used in news, business, and social statistics.
  • Functions as both a noun and a suru-verb (急増する).

The Japanese word 急増 (kyūzō) is a powerful noun and suru-verb that captures the essence of velocity and growth combined. Etymologically, it is composed of two kanji: 急 (kyū), meaning 'sudden' or 'urgent', and 増 (zō), meaning 'increase'. Together, they describe a phenomenon where the quantity, frequency, or degree of something spikes dramatically over a very short period. This isn't just a steady climb; it is a vertical leap on a graph.

Statistical Context
Used primarily in news and business to describe population spikes, sales surges, or rising infection rates.
Visual Representation
Think of a hockey-stick graph where the line suddenly points toward the ceiling.

最近、この町では観光客が急増しています。(Recently, the number of tourists in this town has been increasing rapidly.)

— Common usage in local news

In a sociological sense, kyūzō often carries a nuance of surprise or even alarm. When something increases this fast, it often outpaces the infrastructure meant to handle it. For instance, if users of a new app kyūzō, the servers might crash. If the elderly population kyūzō, the healthcare system faces immediate pressure. It is a word that demands attention because the speed of change is just as important as the change itself.

注文が急増して、在庫がなくなりました。(Orders spiked, and we ran out of stock.)

Kanji Breakdown: 急
Meaning: Hurry, sudden, steep. Radical: 心 (heart/mind).
Kanji Breakdown: 増
Meaning: Increase, add. Radical: 土 (earth/ground).

SNSの利用者が世界中で急増した。(The number of SNS users increased rapidly worldwide.)

Ultimately, 急増 is about the 'steepness' of the curve. It is a word of the modern era, where information, people, and trends move faster than ever before. Whether discussing the 'kyūzō' of electric vehicles or the 'kyūzō' of remote workers, it remains an essential term for describing the dynamic shifts in our contemporary world.

Using 急増 (kyūzō) correctly requires understanding its grammatical flexibility as both a noun and a suru-verb. In most cases, you will see it paired with the particle (ga) to indicate what is increasing, followed by する (suru) or its various forms.

Pattern 1: [Noun] + が + 急増する
The most common way to describe a trend. 'The [Noun] is increasing rapidly.'
Pattern 2: [Noun] + の + 急増
Using it as a noun to describe a phenomenon. 'The rapid increase of [Noun].'

電気代が急増して困っています。(I'm in trouble because my electricity bill has spiked.)

One key aspect of kyūzō is its formal tone. While you can use it in daily conversation (like the electricity bill example), it shines in professional reports, news broadcasts, and academic writing. It provides a level of precision that 'fueta' (increased) lacks. When you say kyūzō, you are providing a qualitative description of the speed of that increase.

海外からの投資が急増している。(Investment from overseas is currently surging.)

Common collocations include 需要が急増する (demand surges) and 人気が急増する (popularity spikes). It is rarely used for personal physical growth (like a child getting taller), where kyūseichō (rapid growth) would be more appropriate. Instead, stick to numbers, volumes, and abstract concepts like 'interest' or 'complaints'.

You will encounter 急増 (kyūzō) most frequently in environments where data and trends are discussed. It is a staple of the NHK evening news, business newspapers like the Nikkei, and corporate strategy meetings. If a company's stock price jumps, or if a new virus variant spreads, kyūzō will be the headline word.

「都内の感染者数が急増しています」 (The number of infected people in the city is increasing rapidly.)

— Typical news anchor phrase

In the digital age, you'll also see it on social media analytics. Influencers might talk about their follower count kyūzō-ing after a viral post. In the gaming world, a sudden influx of players to a new server is described as kyūzō. It carries a sense of 'momentum' that is very relevant to the fast-paced nature of the internet.

Business Meetings
'Due to the marketing campaign, inquiries have kyūzō-ed.'
Government Reports
'The kyūzō of vacant houses (akiya) is a social problem.'

Furthermore, in educational settings, teachers use kyūzō when discussing history or geography—for example, the rapid population increase during the Industrial Revolution or the sudden rise in urban density. It is a versatile word that bridges the gap between technical jargon and everyday descriptive language.

While 急増 (kyūzō) is straightforward, learners often confuse it with other 'increase' words. The most common error is using it for things that grow 'large' rather than 'numerous'. For example, you wouldn't say your house kyūzō-ed if you built an extension; that would be kakudai (expansion).

Mistake 1: Confusing with 増加 (zōka)
Zōka is neutral. Kyūzō is fast. Don't use kyūzō for a 1% increase over 10 years.
Mistake 2: Confusing with 急成長 (kyūseichō)
Kyūseichō is for 'growth' (like a company's success or a child's height). Kyūzō is for 'count' (like number of employees).

❌ 背が急増した (My height increased rapidly) — Incorrect usage.

✅ 背が急に伸びた / 急成長した — Correct usage.

Another mistake is the particle usage. Learners sometimes use (wo) instead of (ga). Since kyūzō is an intransitive action (something increases by itself), ga is the standard. You don't 'rapidly increase' something as an object in the same way; you 'cause' it to increase, or the 'number of' something increases.

To truly master 急増 (kyūzō), you should know its neighbors in the Japanese vocabulary. Depending on the intensity and the context, other words might be more precise.

激増 (gekizō)
Even more intense than kyūzō. 'Geki' means 'violent' or 'extreme'. Use this for explosive, astronomical increases.
急騰 (kyūtō)
Specifically used for prices or stock values 'jumping' or 'soaring'.
爆増 (bakuzō)
Slang/Casual. 'Explosive increase'. Common on YouTube titles or social media.

「ビットコインの価格が急騰した」 (The price of Bitcoin soared.)

While kyūzō is the 'standard' professional term, gekizō is used when the speaker wants to emphasize that the increase is overwhelming or problematic. On the other hand, zōka (増加) is the safe, clinical term used when the speed isn't the main point of the sentence.

By choosing between these synonyms, you can convey exactly how 'big' or 'fast' a change is, allowing for much more nuanced communication in both business and academic Japanese.

How Formal Is It?

Difficulty Rating

Grammar to Know

~に伴い (along with)

~によって (due to)

~傾向にある (tend to)

~つつある (in the process of)

Noun + 中 (currently)

Examples by Level

1

テストの点数が急増しました。

Test scores increased rapidly.

Simple past tense of a suru-verb.

2

この町は、観光客が急増しています。

In this town, tourists are increasing rapidly.

Present continuous (~te iru) showing an ongoing trend.

3

最近、雨の日が急増しました。

Recently, rainy days have increased rapidly.

Using 'saikin' (recently) with kyūzō.

4

お店の注文が急増しました。

Orders at the shop increased rapidly.

Subject (chūmon) + ga + kyūzō.

5

ユーチューブの登録者が急増した。

YouTube subscribers increased rapidly.

Casual past tense.

6

冬は風邪をひく人が急増します。

In winter, people who catch colds increase rapidly.

Dictionary form used for general truths.

7

新しいゲームの利用者が急増中だ。

Users of the new game are currently increasing rapidly.

~chū (during/in the middle of) attached to the noun.

8

ゴミの量が急増して困っています。

The amount of trash has increased rapidly and it's a problem.

~te form used to show cause and effect.

1

SNSの普及で、写真の投稿数が急増した。

With the spread of SNS, the number of photo posts spiked.

Noun + de (due to) indicating the cause.

2

暑さのせいで、冷たい飲み物の売り上げが急増している。

Because of the heat, sales of cold drinks are surging.

~no sei de (because of - negative nuance).

3

そのニュースの後、問い合わせが急増した。

After that news, inquiries increased rapidly.

Noun + no ato (after).

4

ペットを飼う家庭が急増しているそうです。

I heard that households with pets are increasing rapidly.

~sō desu (I heard that).

5

オンライン授業の利用が急増しました。

The use of online classes increased rapidly.

Noun + no + noun structure.

6

キャンプに行く人が急増していると聞きました。

I heard that people going camping are increasing rapidly.

~to kikimashita (I heard that).

7

駅前に新しいマンションができて、人口が急増した。

A new apartment was built in front of the station, and the population spiked.

Compound sentence with ~te form.

8

電気自動車の需要が急増しています。

Demand for electric vehicles is increasing rapidly.

Juyō (demand) is a common partner for kyūzō.

1

スマートフォンの普及に伴い、歩きスマホによる事故が急増している。

With the spread of smartphones, accidents caused by using phones while walking are surging.

~ni tomonai (along with/accompanying).

2

不景気の影響で、将来に不安を感じる若者が急増した。

Due to the recession, the number of young people feeling anxious about the future has spiked.

Relative clause describing 'wakamono' (young people).

3

その映画が公開されてから、原作本の売り上げが急増した。

Since that movie was released, sales of the original book have surged.

~te kara (since/after doing).

4

最近、副業を始める会社員が急増しているというデータがある。

There is data showing that office workers starting side jobs are increasing rapidly.

~to iu (that/which says) used to introduce data.

5

キャッシュレス決済の利用者が急増し、現金を使わない人が増えた。

Users of cashless payments surged, and people who don't use cash increased.

Ren'yōkei (stem form) used as a conjunction in formal writing.

6

都市部への人口集中により、家賃が急増している地域もある。

Due to population concentration in urban areas, there are regions where rent is surging.

~ni yori (due to/by).

7

健康志向の高まりから、ジムの入会者が急増した。

Due to rising health consciousness, gym memberships spiked.

~kara (from/due to) indicating the source of the change.

8

AI技術の進化によって、関連する求人が急増している。

With the evolution of AI technology, related job openings are surging.

~ni yotte (by means of/due to).

1

昨今の円安の影響で、日本を訪れる外国人観光客が急増している。

Due to the recent yen depreciation, foreign tourists visiting Japan are surging.

Sakkon (recent days) adds a formal B2-level tone.

2

宅配サービスの需要が急増したことで、物流業界の人手不足が深刻化している。

The surge in demand for delivery services has worsened the labor shortage in the logistics industry.

~koto de (because of the fact that) + shinkokuka (becoming serious).

3

サイバー攻撃の件数が急増しており、企業は対策に追われている。

The number of cyberattacks is surging, and companies are struggling to keep up with countermeasures.

~ni owarete iru (to be busy with/pressed by).

4

高齢者の独居世帯が急増していることは、現代社会の大きな課題である。

The rapid increase in elderly single-person households is a major challenge for modern society.

Using the whole clause as a subject with 'koto wa'.

5

SNSでの誹謗中傷が急増し、法整備の必要性が叫ばれている。

Slander on SNS has surged, and the need for legal frameworks is being called for.

~ga sakebarete iru (is being cried out/demanded).

6

リモートワークの普及により、郊外の住宅需要が急増した。

With the spread of remote work, demand for housing in the suburbs has spiked.

Kōgai (suburbs) and juyō (demand).

7

特定の野菜の価格が急増したのは、長雨による不作が原因だ。

The reason the price of certain vegetables spiked is the poor harvest caused by long rains.

Identifying the 'gen'in' (cause) of the kyūzō.

8

若者の間で、投資への関心が急増している背景には、将来への不安がある。

Behind the surge in interest in investing among young people lies anxiety about the future.

Haikei (background/context) is a key B2 concept.

1

新興国における中間層の急増は、世界経済の勢力図を塗り替えつつある。

The rapid increase of the middle class in emerging nations is redrawing the map of the global economy.

~tsutsu aru (is in the process of).

2

空き家の急増が、地方自治体にとって財政的・安全上の大きな負担となっている。

The surge in vacant houses has become a significant financial and safety burden for local governments.

Abstract noun usage of kyūzō.

3

情報漏洩のリスクが急増する中で、高度なセキュリティ人材の確保が急務となっている。

Amidst the surging risk of information leaks, securing highly skilled security personnel has become an urgent task.

~naka de (amidst/while).

4

プラットフォーム経済の台頭により、ギグワーカーの数が世界的に急増した。

With the rise of the platform economy, the number of gig workers has surged globally.

Taitō (rise/emergence) and gig worker.

5

気候変動の影響で、極端な気象現象の発生頻度が急増しているとの指摘がある。

It has been pointed out that the frequency of extreme weather events is surging due to the impact of climate change.

~to no shiteki ga aru (it has been pointed out that).

6

都市部への一極集中が加速し、地方の過疎化と都市の過密化が同時に急増している。

Unipolar concentration in urban areas is accelerating, with rural depopulation and urban overcrowding both surging simultaneously.

Parallelism of social phenomena.

7

生成AIの普及に伴い、著作権侵害を巡るトラブルが急増しているのが現状だ。

The current situation is that troubles surrounding copyright infringement are surging with the spread of generative AI.

~wo meguru (surrounding/concerning).

8

投機的な資金の流入により、不動産価格が急増し、バブルの懸念が高まっている。

Due to the influx of speculative funds, real estate prices have surged, raising concerns about a bubble.

Tōki-teki (speculative) and ken'en (concern).

1

デジタル・トランスフォーメーションの進展は、データトラフィックの爆発的急増を招いた。

The progress of Digital Transformation has led to an explosive surge in data traffic.

Using 'bakuhatsu-teki' (explosive) to modify kyūzō.

2

格差社会の拡大に伴い、相対的貧困層が急増している事実は看過できない。

The fact that the relative poverty class is surging along with the expansion of the wealth gap cannot be overlooked.

Kanka dekinai (cannot be overlooked).

3

パンデミックが引き金となり、メンタルヘルス不調を訴える患者が急増したことは記憶に新しい。

It is still fresh in our memory that the pandemic triggered a surge in patients complaining of mental health issues.

Hikigane to nari (becoming a trigger).

4

アルゴリズムによる自動取引の普及が、市場のボラティリティの急増に寄与している。

The spread of automated trading by algorithms is contributing to the surge in market volatility.

Kiyo shite iru (is contributing to).

5

少子高齢化の進展は、現役世代の社会保障負担の急増という形で跳ね返ってくる。

The progress of the declining birthrate and aging population will rebound in the form of a surge in the social security burden on the working generation.

Hanekaette kuru (to rebound/come back to).

6

情報の非対称性が解消される一方で、フェイクニュースの急増が民主主義の根幹を揺るがしている。

While information asymmetry is being resolved, the surge of fake news is shaking the very foundations of democracy.

Konkan wo yurugasu (to shake the foundations).

7

バイオテクノロジー分野への投資が急増した背景には、遺伝子編集技術の画期的な進歩がある。

Behind the surge in investment in the biotechnology field lies the breakthrough progress in gene-editing technology.

Kakkiteki (breakthrough/epoch-making).

8

グローバル化の反動として、ナショナリズムを標榜する勢力が急増している現状をどう捉えるべきか。

How should we interpret the current situation where forces advocating nationalism are surging as a backlash against globalization?

Hyōbō suru (to advocate/profess).

Synonyms

激増 急騰 爆増 急に増える 飛躍的増加

Common Collocations

需要が急増する (demand surges)
利用者が急増する (users increase rapidly)
人気が急増する (popularity spikes)
売り上げが急増する (sales surge)
人口が急増する (population spikes)
問い合わせが急増する (inquiries flood in)
感染者が急増する (infections spike)
犯罪が急増する (crime surges)
注文が急増する (orders spike)
アクセスが急増する (web traffic spikes)

Often Confused With

急増 vs 増加 (zōka)

Zōka is any increase; Kyūzō is specifically fast/sudden.

急増 vs 急成長 (kyūseichō)

Kyūseichō is for quality/success; Kyūzō is for quantity/count.

急増 vs 急騰 (kyūtō)

Kyūtō is specifically for prices/stocks.

Easily Confused

急増 vs

急増 vs

急増 vs

急増 vs

急増 vs

Sentence Patterns

Word Family

Related

増加 (zōka)
増やす (fuyasu)
増える (fueru)
増大 (zōdai)
増額 (zōgaku)

How to Use It

nuance

Kyūzō is neutral but often implies a situation that needs management.

limitations

Don't use it for personal height or weight growth; use 'fueru' or 'seichō'.

Common Mistakes
  • Using 'kyūzō' for a slow increase.
  • Using 'wo' instead of 'ga' (e.g., ❌ 人口を急増した).
  • Confusing it with 'kyūtō' (specifically for prices).
  • Using it for physical height growth.
  • Misspelling the kanji for 'zō' (増).

Tips

Report Writing

Use 'kyūzō' to make your business reports sound more analytical and professional.

Kanji Pair

Remember that both kanji (急 and 増) are very common on their own.

Emphasis

Use 'kyūzō' to emphasize that a change was not expected.

News Keywords

This is one of the top 100 words used in Japanese news broadcasts.

Context Clues

If you see a graph in a Japanese article, look for 'kyūzō' in the caption.

Suru-Verb

Don't forget that it behaves like any other suru-verb (kyūzō shita, kyūzō shinai).

Trends

Great word for discussing 'viral' content or trending topics.

Market Analysis

Essential for describing market demand shifts.

Sudden Plus

Think: Sudden (急) + Plus (増).

JLPT Tip

Often appears in the 'reading comprehension' section of the N3/N2 exams.

Memorize It

Word Origin

Cultural Context

NHK often uses this word with red graphics to show urgency.

In 'Keizai' (economics) news, it's a daily keyword.

Practice in Real Life

Real-World Contexts

Conversation Starters

"最近、何が急増していると思いますか?"

"あなたの国で、最近急増している問題は何ですか?"

"電気代が急増して困ったことはありますか?"

"急増している人気の観光地はどこですか?"

"最近、SNSで急増しているトレンドは何ですか?"

Journal Prompts

最近、自分の周りで急増していると感じるものについて書いてください。

もし自分の貯金が急増したら、何をしたいですか?

スマホの利用時間が急増することのメリットとデメリットを考えてください。

Frequently Asked Questions

10 questions

Yes, it can be used for both positive (sales) and negative (crime, infections) things.

It's better to use 'fueru' or 'taijū ga fueta'. 'Kyūzō' sounds like a statistical report.

The opposite is 'kyūgen' (急減), which means a rapid decrease.

Yes, it is typically categorized as JLPT N3 vocabulary.

Yes, you can use the causative form to mean 'to cause a rapid increase'.

'Gekizō' is more extreme and dramatic than 'kyūzō'.

No, it's generally for countable things or measurable trends.

Yes, but mostly when talking about news or general trends.

Usually 'suru' (verb) or 'no' (noun modifier).

No, use 'kasoku' (acceleration) for speed.

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A1

Kyori refers to the physical amount of space between two points or objects. It can also be used figuratively to describe the psychological or emotional gap between people in a relationship.

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