Health check-up - Ningendokku

Japanese: 人間ドック - にんげんどっく

It is a comprehensive medical checkup of the whole body conducted in a short period of time. Although some subjects visit the clinic because they have some subjective symptoms, many visit without any subjective symptoms. The word "dock" is derived from "ship dock," where ships that have completed their voyages are checked for abnormalities in their engines and hulls and undergo necessary repairs. The first medical checkup was opened at the National Tokyo First Hospital in 1954 (Showa 29) with the idea that people also need to check for physical abnormalities that arise during their busy daily lives, regardless of whether they have any subjective symptoms. Since then, medical checkups have become widespread in hospitals all over the country. Traditional health checkups at companies and schools were mainly aimed at early detection of tuberculosis. However, in recent years, attention has been focused on lifestyle-related diseases (adult diseases), such as cardiovascular diseases such as angina pectoris, myocardial infarction, and stroke; digestive diseases such as gastric and duodenal ulcers, hepatitis, and cirrhosis; metabolic diseases such as diabetes, gout, and dyslipidemia; and malignant tumors such as stomach cancer, colon cancer, lung cancer, breast cancer, and uterine cancer. The main purpose of today's medical checkups is to detect these diseases early. Along with these changes in content, the target population has also changed. In other words, while the target population for medical checkups in the past was limited to company employees and school students, in the case of medical checkups, the target population has been expanded to include the general public who do not belong to any organization. However, since medical checkups are not intended to treat illnesses, they are not covered by health insurance, and although there are some subsidy systems from health insurance organizations, companies, and municipalities, all costs are self-paid. For this reason, in the past, hospitalization of around one week was required, but recently, due to time and economic reasons, short-term inpatient checkups of one or two nights or outpatient checkups have become the norm.

[Kazufumi Kimura]

Inspection items

The tests carried out during a medical checkup vary slightly depending on the size of the hospital and the duration of the checkup, but generally there is no big difference. In addition to a general interview (medical history, lifestyle history, occupational history, family history, recent physical condition, etc.) and an internal medical examination (percussion, auscultation, palpation, visual examination, etc.), a systematic examination of each organ in the body is carried out, as follows:

(1) Respiratory system Chest X-rays (frontal and lateral views) are taken to check for the presence of tuberculosis, cancer, and other lesions. If necessary, sputum is collected and histopathological examination is performed to detect the presence of pathogens such as tuberculosis bacteria and to detect cancer cells. Respiratory function tests measure vital capacity and 1-second forced expulsion (the percentage of the volume of air exhaled in the first second after maximum inspiration).

(2) Heart, brain, and vascular system Blood pressure is measured in the usual sitting position, but it can also be measured in the lying or standing position. This is to check for abnormal fluctuations in blood pressure due to body position. In addition to electrocardiograms at rest, the patient is subjected to exercise on a treadmill or other device to check for arrhythmia and angina. Chest and abdominal X-rays are also used to check for abnormalities in the size and shape of the heart and large blood vessels (such as cardiac hypertrophy) and for calcification (calcification due to arteriosclerosis). For the brain, CT scans of the head, MRI scans, MRA scans, and electroencephalograms are used. Fundus photography is also used to observe changes such as arteriosclerosis.

(3) Kidneys and Urinary System Urine tests are used to check for the presence of protein and sugar. In addition, the sediment from centrifugation (what remains after the supernatant is removed from the centrifuge) is examined under a microscope to check for the presence of pathological components such as white blood cells, red blood cells, casts (clotted substances formed within the renal tubules), and bacteria, to screen for kidney disease and diabetes. In addition, kidney function is evaluated by conducting a kidney urine concentrating ability test, a PSP (phenolsulfonphthalein) dye excretion test, and blood tests (for sodium, potassium, chloride, urea nitrogen, creatinine concentration, etc.).

(4) Digestive System: For the esophagus, stomach, and duodenum, a barium contrast examination is performed, and if necessary, a fiberscope is used to examine the characteristics of the mucosa, especially the presence or absence of ulcers and cancer. For the lower digestive tract, such as the small intestine and large intestine, a fecal occult blood test is first performed, and if the result is positive, other tests such as a barium enema and a fiberscope are performed.

(5) Liver, gallbladder and pancreas: This mainly consists of blood chemistry tests (total protein, albumin, globulin, bilirubin, GOT, GPT, LDH, ALP, γ-GTP, ZTT, amylase, etc.), but also checks for the presence of hepatitis B and C viruses, cholecystography to check for gallstones, etc. Abdominal ultrasound is also performed, and an abdominal CT scan may be used if necessary.

(6) Metabolic diseases such as diabetes and gout Fasting blood glucose and _HbA1c measurements, as well as a 50-100 gram glucose tolerance test, are performed to check for impaired glucose tolerance. Blood uric acid levels are also checked to check for hyperuricemia, which is the cause of gout, and serum lipids (cholesterol, triglycerides, etc.) are examined to check for dyslipidemia.

(7) Blood diseases, etc. The presence or absence of anemia is checked by the red blood cell count, hemoglobin concentration, and hematocrit (red blood cell volume percentage), while the presence or absence of infections and various blood diseases is checked by the white blood cell count, percentage (the proportion of each type of white blood cell, such as granulocytes, lymphocytes, and mononuclear cells), and erythrocyte sedimentation rate. In addition, the presence or absence of syphilis, collagen disease, etc. is checked by various serum reactions.

(8) Others: The surgical department mainly performs anorectal examinations and mammograms for breast cancer screening, while the gynecology department mainly performs uterine cancer screening. In addition, the department also performs ophthalmology and otolaryngology examinations as necessary.

The results of these general examinations and tests will be explained to patients by their doctor when they are discharged from the hospital or on a specified date. If any abnormalities are found, patients will be instructed on what they should be careful of in their daily lives. In some cases, more detailed tests or treatments may be required, and patients may be referred to a specialist.

[Kazufumi Kimura]

"Ningen Dock Yearbook 2000" edited by the Ningen Dock Yearbook Editorial Committee (2000, Doctor Forum Publishing, Seiunsha Publishing)" ▽ "Ningen Dock Manual - Key Points for Health Evaluation and Guidance, 3rd Edition (2003, Igaku-Shoin), edited by Tamura Masaki and Tajima Motoo, supervised by Hinohara Shigeaki" ▽ "Health Checkup and Ningen Dock Handbook" edited by Ogawa Teppei, Saruta Takao and Tamura Masaki (2004, Chugai Igaku-sha), supervised by Hinohara Shigeaki

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

Japanese:

短期間に集中して行う全身の総合的な健康診断をいう。対象者は、なんらかの自覚症状があるために受診することもあるが、多くは、まったく自覚症状がない状態で受診する。「ドック」の語は、航海を終えた船舶がエンジンや船体の異常をチェックし、必要な修理を受ける「船舶ドック」から転用されたものである。人間も、肉体的・精神的に多忙な日常生活を過ごす間に生じてくる身体異常を、自覚症状の有無にかかわらずチェックする必要があるという主旨から、1954年（昭和29）国立東京第一病院に最初の人間ドックが開設された。以来、人間ドックは各地の病院に広く普及している。従来からある企業や学校単位での健康診断は、結核の早期発見が主目的であった。しかし、最近では、狭心症・心筋梗塞(こうそく)・脳卒中などの循環器疾患、胃・十二指腸潰瘍(かいよう)・肝炎・肝硬変などの消化器疾患、糖尿病・痛風(つうふう)・脂質異常症などの代謝性疾患、胃癌(がん)・大腸癌・肺癌・乳癌・子宮癌などの悪性腫瘍(しゅよう)といった、いわゆる生活習慣病（成人病）が注目されるようになってきている。今日の人間ドックがもつもっとも大きな目的は、これら疾患の早期発見にある。こうした内容の変化とともに、対象とする人々も変わってきた。すなわち、これまでの健康診断の対象者は、企業の従業員や学校の学生・生徒に限られていたが、人間ドックの場合、その対象者は、組織に属していない一般の人々にまで広げられたわけである。しかし、人間ドックは病気の治療を目的としていないため、健康保険の適用はなく、一部健康保険団体、企業、市町村よりの助成制度があるが、すべて自己負担となる。このため、従来は1週間程度の入院を必要としたが、最近では、時間的・経済的に縮小した1泊ないし2泊の短期入院ドックや外来ドックが主となっている。

［木村和文］

検査項目

人間ドックで行われる検査項目は、病院の規模の大小や、期間の長短などにより若干の違いはあるが、基本的には大差はない。一般的な問診（既往歴・生活歴・職業歴・家族歴・最近の身体状況など）、内科診察（打診・聴診・触診・視診など）のほかに、次のような身体各臓器の系統的な検査を行う。

(1)呼吸器系　胸部レントゲン写真（正面像・側面像）で、結核、癌などの病変の有無を調べる。さらに必要ならば、喀痰(かくたん)を採取し、結核菌などの病原菌の有無や、癌細胞の発見を目的として病理組織学的検査を行う。呼吸機能検査では、肺活量、1秒率（最大吸気から最初の1秒間に吐き出される気量の割合）などを測定する。

(2)心・脳・血管系　血圧測定は、通常の坐位(ざい)血圧のほか、臥位(がい)や立位で測定することもある。これは、体位による血圧の異常な変動がないかどうかをチェックするためである。心電図は、安静時心電図のほかに、トレッドミルなどで運動負荷をかけ、不整脈や狭心症の有無をチェックする。また、胸部・腹部レントゲン写真から、心・大血管系の大きさ・形の異常（心肥大など）、石灰化（動脈硬化による石灰沈着）の有無を調べる。脳については、頭部のCTスキャン、MRI検査、MRA検査、脳波検査などを行う。また、眼底撮影により細動脈硬化などの変化を観察する。

(3)腎(じん)・尿路系　尿検査では、タンパク・糖の有無を調べる。また、遠心分離した沈渣(ちんさ)（遠心分離機にかけ、上澄みを除いたあとに残るもの）を顕微鏡で観察し、白血球、赤血球、円柱（腎尿細管内でできる凝固物質）、細菌などの病的成分の有無を調べ、腎疾患や糖尿病などのスクリーニング（選別）を行う。また、腎臓の尿濃縮力試験、PSP（フェノールスルホンフタレイン）色素排泄(はいせつ)試験、血液検査（ナトリウム、カリウム、塩素、尿素窒素、クレアチニン濃度など）を実施して、腎機能の評価を行う。

(4)消化管系　食道・胃・十二指腸は、バリウムによる造影検査を行い、必要なら、ファイバースコープにより、粘膜の性状、とくに潰瘍・癌の有無を調べる。小腸・大腸など下部消化管については、まず糞便(ふんべん)の潜血検査を行い、陽性の場合は、注腸造影、大腸ファイバースコープなどの検査を行う。

(5)肝臓・胆嚢(たんのう)・膵臓(すいぞう)　主として血液化学検査（総タンパク、アルブミン、グロブリン、ビリルビン、GOT、GPT、LDH、ALP、γ‐GTP、ZTT、アミラーゼなど）となるが、ほかにB型・C型肝炎ウイルスの有無、胆嚢造影による胆石の有無なども調べる。腹部超音波エコー検査も行われ、必要により腹部CTスキャンを用いることもある。

(6)糖尿病・痛風などの代謝性疾患　空腹時血糖、HbA₁c測定や、50～100グラムのブドウ糖負荷試験を行って、耐糖能異常の有無を調べる。また、血中の尿酸値の検査から、痛風のもととなる高尿酸血症の有無がチェックされるほか、血清脂質（コレステロール、中性脂肪など）を調べて、脂質異常症の有無もチェックされる。

(7)血液疾患など　赤血球数・血色素濃度・ヘマトクリット（赤血球容積率）によって貧血症の有無を、白血球数・百分比（顆粒(かりゅう)球・リンパ球・単核球など白血球の種類別の存在割合）・血沈によって感染症、各種血液疾患の有無をチェックする。また、各種血清反応により梅毒、膠原(こうげん)病などの有無も調べる。

(8)その他　外科では直腸肛門(こうもん)診、マンモグラフィーによる乳癌検診を、婦人科では子宮癌検診を中心とした診察を行う。また、必要に応じて眼科、耳鼻咽喉(いんこう)科などの診察を行う。

　これらの全身的な診察・検査の結果は、退院時、または指定された日に、担当医より受診者に説明される。もし、異常が発見された場合には、今後の生活において注意すべき点が指示される。場合によっては、より詳しい検査や治療が必要となり、専門医に紹介されることもある。

［木村和文］

『人間ドック年鑑編集委員会編『人間ドック年鑑2000』（2000・ドクターフォーラム出版会、星雲社発売）』▽『日野原重明監修、田村政紀・田嶋基男編『人間ドックマニュアル――健康評価と指導のポイント』第3版（2003・医学書院）』▽『日野原重明監修、小川哲平・猿田享男・田村政紀編著『健診・人間ドックハンドブック』（2004・中外医学社）』