Editing Ulcerative colitis (section)

====Severity of disease====
In addition to the extent of involvement, UC is also characterized by severity of disease.<ref name=ACG_Guidelines_2019 /> Severity of disease is defined by symptoms, objective markers of inflammation (endoscopic findings, blood tests), disease course, and the impact of the disease on day-to-day life.<ref name=ACG_Guidelines_2019 /> Most patients are categorized through endoscopy and fecal calprotectin levels. Indicators of low risk for future complications in mild and moderate UC include the following parameters: exhibiting less than 6 stools daily and lack of fever/weight loss. Other indicators include lack of extraintestinal symptoms, low levels of the inflammatory markers [[C-reactive protein]] (CRP), and [[erythrocyte sedimentation rate]] (ESR), and fecal [[calprotectin]], and later age of diagnosis (over 40 years).<ref name=":2">{{cite web |title=UpToDate |url=https://www.uptodate.com/contents/medical-management-of-low-risk-adult-patients-with-mild-to-moderate-ulcerative-colitis?search=ulcerative%20colitis&source=search_result&selectedTitle=2~150&usage_type=default&display_rank=2 |access-date=8 November 2022 |website=www.uptodate.com}}</ref> Mild disease correlates with fewer than four stools daily; in addition, mild urgency and rectal bleeding may occur intermittently.<ref name=ACG_Guidelines_2019 />  Mild disease lacks [[Systemic disease|systemic]] signs of toxicity (e.g. fever, chills, weight changes) and exhibits normal levels of the serum inflammatory markers ESR and CRP.<ref name=":2" />

Moderate to severe disease correlates with more than six stools daily, frequent bloody stools and urgency.<ref name=ACG_Guidelines_2019 /> Moderate abdominal pain, low-grade [[fever]], {{convert|38|to|39|C|F}}, and anemia may develop.<ref name=ACG_Guidelines_2019 /> ESR and CRP are usually elevated.<ref name=ACG_Guidelines_2019 />

The Mayo Score, which incorporates a combination of clinical symptoms (stool frequency and amount of rectal bleeding) with endoscopic findings and a physicians assessment of severity, is often used clinically to classify UC as mild, moderate or severe.<ref name="Gros 2023" />

Acute-Severe Ulcerative Colitis (ASUC) is a severe form which presents acutely and with severe symptoms. This fulminant type is associated with severe symptoms (usually diarrhea, rectal bleeding and abdominal pain) and is usually associated with systemic symptoms including fever.<ref name="Gros 2023" /> It is associated with a high mortality rate as compared to milder forms of UC, with a 3-month and 12 month mortality rate of 0.84% and 1% respectively.<ref name="Gros 2023" /> People with fulminant UC may have inflammation extending beyond just the mucosal layer, causing impaired colonic motility and leading to [[toxic megacolon]]. Toxic megacolon represents a medical emergency, one often treated surgically. If the [[serous membrane]] is involved, a colonic [[gastrointestinal perforation|perforation]] may ensue, which has a 50% mortality rate in people with UC.<ref>{{cite web |title=UpToDate |url=https://www.uptodate.com/contents/clinical-manifestations-diagnosis-and-prognosis-of-ulcerative-colitis-in-adults?search=clinical%20manifestation%20of%20ulcerative%20colitis&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1 |access-date=9 November 2022 |website=www.uptodate.com}}</ref> Other complications include [[hemorrhage]], [[venous thromboembolism]], and secondary infections of the colon including ''[[C. difficile]]'' or [[cytomegalovirus]] colitis.<ref name="Gros 2023" />

Ulcerative colitis may improve and enter remission.<ref name=ACG_Guidelines_2019 />