Editing Appendicitis (section)

===Laboratory tests===

While there is no laboratory test specific for appendicitis, a [[complete blood count]] (CBC) is done to check for signs of infection or inflammation. Although 70–90 percent of people with appendicitis may have an elevated [[white blood cell count|white blood cell (WBC) count]], many other abdominal and pelvic conditions can cause the WBC count to be elevated.<ref name=CDEM>{{cite web|title=Appendicitis |first=Charmaine |last=Gregory |work=CDEM Self Study Modules |publisher=Clerkship Directors in Emergency Medicine |date=2010 |url=http://www.cdemcurriculum.org/ssm/gi/appy/appy.php |url-status=usurped |archive-url=https://web.archive.org/web/20131130062201/http://www.cdemcurriculum.org/ssm/gi/appy/appy.php |archive-date=2013-11-30 }}</ref> However, a high [[White blood cell count|WBC count]] may not alone represent a solid indicator of appendicitis but rather an inflammation<ref name=Shogilev2014 /> but the neutrophil ratio was more sensitive and specific for acute appendicitis.<ref>{{cite journal |last1=Şahbaz |first1=NA |last2=Bat |first2=O |last3=Kaya |first3=B |last4=Ulukent |first4=SC |last5=İlkgül |first5=Ö |last6=Özgün |first6=MY |last7=Akça |first7=Ö |title=The clinical value of leucocyte count and neutrophil percentage in diagnosing uncomplicated (simple) appendicitis and predicting complicated appendicitis. |journal=Ulusal Travma ve Acil Cerrahi Dergisi = Turkish Journal of Trauma & Emergency Surgery|date=November 2014 |volume=20 |issue=6 |pages=423–426 |doi=10.5505/tjtes.2014.75044 |pmid=25541921|doi-access=free }}</ref> Several routine and non-routine laboratory tests have been investigated for discriminating simple and complicated appendicitis, but their diagnostic accuracy is uncertain.<ref>{{Cite journal |last1=Sikander |first1=Binyamin |last2=Rosenberg |first2=Jacob |last3=Fonnes |first3=Siv |date=May 2023 |title=Individual biomarkers in the blood are not yet applicable in diagnosing complicated appendicitis: A scoping review |url=https://linkinghub.elsevier.com/retrieve/pii/S0735675723000839 |journal=The American Journal of Emergency Medicine |language=en |volume=67 |pages=100–107 |doi=10.1016/j.ajem.2023.02.016|pmid=36842426 }}</ref>

In children, [[Neutrophil to lymphocyte ratio|neutrophil-lymphocyte ratio (NLR)]] demonstrates a high degree of accuracy in the diagnosis of acute appendicitis and distinguishes complicated appendicitis from simple appendicitis.<ref>{{cite journal |last1=Prasetya |first1=D |last2=Rochadi |last3=Gunadi |title=Accuracy of neutrophil lymphocyte ratio for diagnosis of acute appendicitis in children: A diagnostic study. |journal=Annals of Medicine and Surgery |date=December 2019 |volume=48 |pages=35–38 |doi=10.1016/j.amsu.2019.10.013 |pmid=31687137|pmc=6820073 }}</ref> 75–78 percent of the patients have [[neutrophilia]].<ref name="Sign"/> Delta-neutrophil index (DNI) is a valuable parameter that helps in the diagnosis of histologically normal appendicitis and distinguishing between simple and complicated appendicitis.<ref>{{cite journal |last1=Shin |first1=DH |last2=Cho |first2=YS |last3=Cho |first3=GC |last4=Ahn |first4=HC |last5=Park |first5=SM |last6=Lim |first6=SW |last7=Oh |first7=YT |last8=Cho |first8=JW |last9=Park |first9=SO |last10=Lee |first10=YH |title=Delta neutrophil index as an early predictor of acute appendicitis and acute complicated appendicitis in adults. |journal=World Journal of Emergency Surgery|date=2017 |volume=12 |pages=32 |doi=10.1186/s13017-017-0140-7 |pmid=28747992 |pmc=5525197 |doi-access=free }}</ref>

A [https://medlineplus.gov/lab-tests/c-reactive-protein-crp-test/ C-reactive protein (CRP) blood test] will be ordered by the doctor to find out if there are any further causes of inflammation.<ref name="NIDDK" /> The C-reactive protein/albumin (CRP/ALB) ratio can be a reliable predictor of complicated appendicitis.<ref>Zhao, X., Yang, J. and Li, J. (2023) The predictive value of the C-reactive protein/albumin ratio in adult patients with complicated appendicitis. Journal of Laboratory Medicine. https://doi.org/10.1515/labmed-2023-0069</ref>

The [[urinalysis]] is important for ruling out a urinary tract infection as the cause of abdominal pain. The presence of more than 20 WBC per high-power field in the urine is more suggestive of a urinary tract disorder.<ref name=CDEM/>

If the patient is a female, a [[pregnancy test]] will be ordered.<ref name="NIDDK" />