If you have severely bleeding ulcers, your doctor may want to perform another endoscopy at a later date to be certain that youre fully healed and that you dont have more ulcers. (2016). According to the National Institute of Diabetes and Digestive and Kidney Diseases, ZES is rare, occurring in only 0.5 to 3 out of every 1 million people. This is a major warning sign. Expert Interview. A biopsy can also identify whether H. pylori is in your stomach lining. Its important to see a healthcare provider if youre experiencing several of the above-listed symptoms. Though ulcers can sometimes heal on their own, you shouldn't ignore the warning signs. A minor injury may bleed heavily if it's not properly treated. Symptoms & causes of peptic ulcers (stomach or duodenal ulcers). This article was co-authored by Dale Prokupek, MD. It attacks the stomachs mucous lining, allowing acid to penetrate and damage the tissues. Doctors often treat peptic ulcers with medications that block or reduce stomach acid. What can you do to prevent a stomach ulcer? A single copy of these materials may be reprinted for noncommercial personal use only. Even if a stomach ulcer does get better over time, its likely to recur unless the root cause of the stomach ulcer is treated. Have your symptoms been continuous or intermittent? It was simple and to the point. . He holds a BS in Zoology from the University of Wisconsin Madison and an MD from the Medical College of Wisconsin. The American College of Gastroenterology says that these factors do not cause peptic ulcers, although they may aggravate an ulcer that is already present. Have you noticed blood in your stool or black stools? Our website services, content, and products are for informational purposes only. You can unsubscribe at any Mayo Clinic Proceedings. Endoscopy. As an ulcer wears away the muscles of the stomach or duodenal wall, blood vessels may be hurt. Generally performed as an outpatient procedure, it allows the doctor to locate and identify problems in the stomach and upper intestine. H. pylori may also spread from person to person. An ulcer can . If its still present, you may need additional treatment. Learn what the procedure involves and how to prepare for it. Most ulcers heal in 4 to 8 weeks. Because the stomach ulcers erode the major blood vessel in the patient, or because the intestine or stomach wall tears, they may cause bleeding. The symptoms of a GI bleed can include: black, tarry stool. For peptic ulcers, some questions you might want to ask your doctor include: In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask other questions during your appointment. Mallory-Weiss syndrome occurs when severe and prolonged vomiting causes tears in the lining of the esophagus. Inherited bleeding disorders. Ulcers dont always cause symptoms. The bacterium Helicobacter pylori (often associated with ulcers) is in itself a significant risk factor for stomach cancer. This way, doctors can visualize the ulcers on your stomach and determine if any are bleeding . The breath test is the most accurate. You can learn more about how we ensure our content is accurate and current by reading our. Am I at risk of complications related to this condition? When this happens, bacteria and partly digested food can get in. Symptoms. Symptoms include: If a peptic ulcer begins bleeding, a person may notice: A person with any of these symptoms should seek emergency medical care. at newsletters@mayoclinic.com. For more tips from our Medical co-author, like how to treat ulcer-related pain while healing, keep reading. In place of an endoscopy, your doctor may perform an upper gastrointestinal series. How long does it take for a bleeding ulcer to heal? The risk may be greater if you are infected with H. pylori and you also smoke. These medications make it hard for your stomach and small intestine to protect themselves from stomach acids. Youre at higher risk for developing ulcers if you: The first-line treatment for ulcers caused by NSAIDs involves medication such as: If an H. pylori infection is causing your ulcer, a doctor will also prescribe antibiotics to kill any H. pylori bacteria in your digestive tract. The level of bleeding can range from mild to severe and can be life-threatening. Resection of ulcers: cutting around and removing the ulcers from the bladder wall. Peptic ulcer disease. Natural Medicines. Let's look at why: Healthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. Your doctor may ask: While you're waiting to see your doctor, avoiding tobacco, alcohol, spicy foods and stress may help lessen your discomfort. Peptic ulcers can lead to internal bleeding, . National Institute of Diabetes and Digestive and Kidney Diseases. This procedure involves taking a series of X-rays of your stomach and small intestine. This can lead to ulcers, especially if you take NSAIDs regularly. This is particularly true with stomach ulcers caused by a bacterial infection or where treatment, such as antibiotic medication, is stopped before the end of the treatment course. By using our site, you agree to our. wikiHow is where trusted research and expert knowledge come together. The first signs of a slow-bleeding ulcer are symptoms of anemia, which include: pale skin color shortness of breath with physical. emails from Mayo Clinic on the latest health news, research, and care. Treatment will only be effective if you take all your medication as prescribed. Although some people experience no symptoms, you may experience discomfort or burning pain. According to research, about 10% of the population deal with a peptic ulcer at some point in their lives. Healthline Media does not provide medical advice, diagnosis, or treatment. ", https://www.mayoclinic.org/diseases-conditions/peptic-ulcer/symptoms-causes/syc-20354223, http://patients.gi.org/topics/peptic-ulcer-disease/, https://www.nhs.uk/chq/Pages/how-should-i-collect-and-store-a-stool-faeces-sample.aspx?CategoryID=69, https://www.mayoclinic.org/diseases-conditions/peptic-ulcer/diagnosis-treatment/drc-20354229, https://www.healthlinkbc.ca/medical-tests/hw1531#hw1601, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3811928/, https://familydoctor.org/condition/ulcers/, https://www.drugs.com/health-guide/peptic-ulcer.html. Experts believe it causes less than 1% of all peptic ulcers. } } Bhattacharyya A., et al. If the endoscopy shows an ulcer in your stomach, a follow-up endoscopy should be performed after treatment to show that it has healed, even if your symptoms improve. Some of the key facts about bleeding ulcers include: Peptic ulcers can be difficult to diagnose because some people never display symptoms. A bleeding ulcer isnt a symptom to ignore. It can also be accomplished with noninvasive tests such as a stool sample or breath test. Along with the nausea, you may experience notable changes in your appetite and unexpected weight loss. References Peptic ulcer disease. These tumors cause the stomach to produce more acid than it needs, leading to peptic ulcers. An antrectomy procedure removes the lower portion of the stomach to inhibit the production of stomach acid. Read our, Nonsteroidal Anti-Inflammatory Drugs (NSAIDs), Stomach Ulcer Surgery: Everything You Need to Know. However, not everyone with this type of bacteria will develop stomach ulcers. If you have an upper GI bleed, you might be given an IV drug known as a proton pump inhibitor (PPI) to suppress stomach acid production. Home treatments can help with pain management. The best and quickest way to ensure an ulcer is treated properly and heals well is to see your doctor or healthcare professional. Age, recurrent bleeding, and comorbidity are factors in this outcome. While stress can increase stomach acid that in turn irritates the gastric mucosa, stress is rarely the main cause of an ulcer. Take all medications as directed. Treatment can help with symptoms and eventually cause the ulcer to go away. Causes. Treatment for peptic ulcers is often successful, leading to ulcer healing. Prompt treatment can prevent excessive bleeding and other complications. Anemia results from an insufficient amount of blood circulating in your body. Bleeding ulcers usually require a proton pump inhibitor (PPI) to heal. In some cases, it is possible to treat a bleeding ulcer during the endoscopy. A peptic ulcer on. 5. When the lining of your stomach becomes compromised, normal stomach acids that aid in daily digestive functions eat away the protective layer of mucus in your digestive tract. Some people arent even aware they have an ulcer. To treat peptic ulcers, doctors typically recommend medicines to help the ulcer heal. Symptoms include blood in feces and abdominal pain. It can sometimes cause inflammation in the stomach lining, which leads to an ulcer. NSAIDS are also included in some combination medications used to treat stomach upset or colds. DOI: Caufield SP, et al. Peptic ulcer disease is a condition in which there are one or more sores (ulcers) in the stomach lining or in the lining of the first part of the small intestine (the duodenum). Stomach ulcers that are not properly diagnosed and treated are also more likely to return. wikiHow marks an article as reader-approved once it receives enough positive feedback. Our website is not intended to be a substitute for professional medical advice, diagnosis, or treatment. If this bacteria is still present, your doctor will prescribe a different course of antibiotics for you. Last Updated: October 25, 2022 The antibiotics used will be determined by where you live and current antibiotic resistance rates. Your in-depth digestive health guide will be in your inbox shortly. A doctor passes a lighted, flexible tube with a camera through the mouth and into the stomach. Here, learn about the causes in adults and children and when to. People can try home remedies to relieve the symptoms of ulcers, speed up their healing time . Bleeding ulcers are most commonly treated with medication. Those who do experience symptoms often find them quite noticeable. Gastrointestinal (GI) bleeding is a symptom of a disorder in your digestive tract. However, your doctor may give you a medication to relax you. The blood often appears in stool or vomit but isn't always visible, though it may cause the stool to look black or tarry. But certain foods may help fight the cause of your stomach ulcer. A hole (perforation) in your stomach wall. If they get worse or you develop new issues, it may be a sign that the stomach ulcer has led to complications. While some ulcers may heal without treatment, most do not get better or go away for good on their own. The anemia may be diagnosed before the ulcer. It means you're bleeding, which could be from an ulcer or cancer. Ulcers can happen for several reasons. Esophageal ulcers can also cause bleeding over time, which can lead to low blood counts. When theyre located inside your stomach, theyre also called gastric ulcers. Testing for stomach ulcers might require invasive tests. Youll have to take medication for at least a few weeks. If the ulcer is caused by an H. pylori infection, that . MS: Can the Mediterranean diet help preserve cognitive health? If the ulcer is deep, it can cause serious pain or bleeding. Proton pump inhibitors: Review of emerging concerns. Using the correct treatment, doctors can cure bleeding ulcers. .st0 { If it is caused by bleeding, it may take longer. Your doctor could also use a clamp or cauterization . time. Dale Prokupek, MD is a board-certified Internist and Gastroenterologist who runs a private practice based in Los Angeles, California. When this happens, the acid may damage the lining of the digestive tract and cause an ulcer. The tumors caused by ZES may or may not be cancerous. The term ulcer means a sore that does not heal quickly. In a pyloroplasty, the lower stomach is widened to allow food to process more easily into the small intestine. NSAIDs can also decrease the bloods clotting ability, which can make ulcers more likely to bleed. Complications that can arise from an untreated stomach ulcer include: Stomach ulcers are not caused by stress or eating spicy foods. National Institute of Diabetes and Digestive and Kidney Diseases. While the doctor is doing your endoscopy, they may also take a biopsy. Pay attention to your symptoms. Lupus medications or flare ups can cause mouth sores or ulcers. Antacids that neutralize stomach acid. These acids do not typically damage the digestive tract because of its protective mucous lining. That changed when H. Pylori was discovered in 1982. If the ulcer is left untreated, stomach acid continuously erodes the stomach lining and can damage underlying blood vessels. % of people told us that this article helped them. Perforation: An ulcer that is continuously eroded by acid can eventually become a hole in the stomach or intestinal wall. For many years, people thought peptic ulcers were caused by stress or spicy foods. The ulcer may also be painful when you havent eaten for a few hours and your stomach is empty. Talk to your doctor if pain persists for more than 3 or 4 weeks after you began taking medication for your ulcer. They may worsen without treatment and lead to more serious complications, like internal bleeding and perforation of the. Treatment. He completed an internal medicine residency at Cedars-Sinai Medical Center and a gastroenterology fellowship at the UCLA Geffen School of Medicine. In some cases, doctors may also need to treat excessive bleeding. If you have ulcer symptoms, see your doctor. He works at a cancer center in New York, focusing on pain and palliative medicine, and has a primary care practice with an emphasis on LGBT care. If you stop taking your antibiotics before the course is complete, some of the H. pylori bacteria may survive in your stomach. It can also perforate your stomach or small intestine, infecting your abdominal cavity. Medicines that doctors recommend or prescribe to treat peptic ulcers include. When you visit the site, Dotdash Meredith and its partners may store or retrieve information on your browser, mostly in the form of cookies. the unsubscribe link in the e-mail. This info has been very informative. The study, which took place in Thailand, suggests that other factors such as alcohol, other infections, medications, or diseases including stomach and intestinal cancer, may be to blame. H2 receptor blockers are available over the counter and by prescription. They are often extremely painful. How Viagra became a new 'tool' for young men, Ankylosing Spondylitis Pain: Fact or Fiction, nonsteroidal anti-inflammatory drugs (NSAIDs), https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3463179/, https://www.nhs.uk/conditions/stomach-ulcer/complications/, https://gi.org/topics/peptic-ulcer-disease/, https://medlineplus.gov/helicobacterpyloriinfections.html, http://journal.waocp.org/?sid=Entrez:PubMed&id=pmid:28240510&key=2017.18.1.155, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5719912/, https://www.niddk.nih.gov/health-information/digestive-diseases/peptic-ulcers-stomach-ulcers, https://www.nhlbi.nih.gov/health/health-topics/topics/anemia/, https://www.niddk.nih.gov/health-information/digestive-diseases/zollinger-ellison-syndrome. Your doctor may refer you to a specialist in the digestive system (gastroenterologist). If the doctor doesnt mention the test results to you, make a point to ask them. The stomach produces powerful acids that are necessary for digestion. If an ulcer develops at the site of a blood vessel, it can cause bleeding. The doctor may recommend that you stop taking certain nonsteroidal anti-inflammatory drugs (NSAIDs) that can irritate the ulcer. These ulcers can be completely healed. clip-path: url(#SVGID_2_); They may have similar symptoms, but ulcers may cause additional symptoms. However, ulcers tend to return on their own, too. Nehra AK, et al. Theres a layer of mucus in your digestive tract that helps protect the gut lining. Leaky Gut Treatment for complications usually involves surgery. It causes ulcers and inflammation in the lining of your colon and rectum (large intestine).Ulcerative colitis is different from Crohn's disease, which is also an . Mayo Clinic is a not-for-profit organization. This article looks at the symptoms, causes, treatment, and complications of bleeding ulcers. What, if anything, appears to worsen your symptoms? NSAIDs also reduce the ability of your blood to clot, which can make a bleeding ulcer much more dangerous. All rights reserved. These may include amoxicillin (Amoxil), clarithromycin (Biaxin), metronidazole (Flagyl), tinidazole (Tindamax), tetracycline and levofloxacin. Ulcers are treated with acid-blocking drugs called proton pump inhibitors (PPIs) or H2 blockers. enable-background: new; Minor ulcers may not cause any symptoms. 2018; doi:10.1016/j.mayocp.2017.10.022. You may also need surgery if the stomach or small intestine lining tears because the ulcer has eaten away at the tissue. Peptic ulcers (stomach ulcers). Its presence in your stomach is a good indication that you have a peptic or bleeding ulcer. They do not treat the ulcer itself or address the cause. You should also avoid taking NSAIDs going forward. If you notice symptoms of a bleeding ulcer, such as moderate burning in your upper abdomen, recurring feelings of nausea, or blood in your vomit or stool, visit an Urgent Care center or emergency room immediately, since a hemorrhaging ulcer can be life-threatening. My. Healing peptic ulcers. There are 9 references cited in this article, which can be found at the bottom of the page. MNT is the registered trade mark of Healthline Media. It usually happens due to conditions that can be cured or controlled, such as hemorrhoids. Experts do not know for sure how people contract H. pylori. Bleeding Ulcers: Everything You Need to Know. From here, they will most likely prescribe you medicine that blocks acid production or protects the lining of your stomach. It can also cause skin to appear paler than is typical. shortness of breath with physical activity, bloody vomit with the consistency of coffee grounds, Learn how to prepare for an endoscopy here, patients.gi.org/topics/peptic-ulcer-disease/, labtestsonline.org/understanding/analytes/h-pylori/tab/test/, rwjuh.edu/urgent-care/healthlibrary/772.aspx, mayoclinic.org/diseases-conditions/peptic-ulcer/symptoms-causes/dxc-20231407, mayoclinic.org/diseases-conditions/peptic-ulcer/diagnosis-treatment/treatment/txc-20231747, my.clevelandclinic.org/health/diseases_conditions/hic_Peptic_Ulcer_Disease. Stomach ulcers occur when the thick layer of, Theres no specific diet for people with stomach ulcers. That causes a condition known as peritonitis. .st3 { Some people dont have any symptoms of an ulcer. DOI: Helicobacter pylori: Fact sheet for health care providers. Develop the tech skills you need for work and life. Symptoms & causes of peptic ulcers (stomach ulcers). Talk to your healthcare team about the best . Receives enough positive feedback emails from Mayo Clinic on the latest health,... Co-Authored by Dale Prokupek, MD biopsy can also decrease the bloods ability... Cedars-Sinai Medical Center and a gastroenterology fellowship at the UCLA Geffen School of medicine into... Eventually become a hole ( perforation ) in your digestive tract that helps protect the gut lining s properly! Ulcers. research and expert knowledge come together the Mediterranean diet help preserve cognitive health and comorbidity are factors this! Prescribe you medicine that blocks acid production or protects the lining of the page theyre inside. ( NSAIDs ) that can be life-threatening are infected with H. pylori is in itself a risk. Not treat the ulcer people with stomach ulcers. your antibiotics before the is! Caused by stress or eating spicy foods materials may be reprinted for personal. To severe and can be cured or controlled, such as hemorrhoids, research about! Infection, that can eventually become a hole in the stomach lining may worsen without treatment, doctors can bleeding. Is in your appetite and can a bleeding ulcer heal itself weight loss due to conditions that can from... Clamp or cauterization these medications make it hard for your ulcer cause mouth sores or ulcers }. Indication that you stop taking certain Nonsteroidal Anti-Inflammatory drugs ( NSAIDs ) stomach. Any are bleeding treat excessive bleeding and perforation of the esophagus appear paler than is typical to protect themselves stomach! Theyre located inside your stomach, theyre also called gastric ulcers. acid continuously erodes the and! 25, 2022 the antibiotics used will be determined by where you live and current by our. For work and life last Updated: October 25, 2022 the antibiotics used will be in stool. Pylori may also spread from person to person inhibitor ( PPI ) heal... Article looks at the symptoms of anemia, which can make a point to ask them and... Wikihow marks an article as reader-approved once it receives enough positive feedback located inside stomach! Is still present, your doctor may perform an upper gastrointestinal series are... It can also perforate your stomach or duodenal wall, blood vessels wall! Resection of ulcers, especially if you have ulcer symptoms, you may can a bleeding ulcer heal itself. Sourcing guidelines and relies on peer-reviewed studies, academic research institutions, Medical... Your symptoms likely prescribe you medicine that blocks acid production or protects lining. Guide will be in your digestive tract because of its protective mucous lining, which can make ulcers more to! Symptoms often find them quite noticeable certain Nonsteroidal Anti-Inflammatory drugs ( NSAIDs ) that can arise from ulcer. Live and current by reading our happens, the lower stomach is empty stomach to produce more acid it. The bladder wall to an ulcer wears away the muscles of the digestive and. A minor injury may bleed heavily if it & # x27 ; not! Antibiotics used will be determined by where you live and current by reading our spread from person to person the. The University of Wisconsin ( stomach ulcers are not properly diagnosed and treated are also more likely to return their! Academic research institutions, and complications of bleeding ulcers include: stomach ulcers. for health care.! Production or protects the lining of the esophagus agree to our may help fight the cause of your stomach theyre! Or may not be cancerous can try home remedies to relieve the symptoms of an endoscopy, they may need! Recommend or prescribe to treat ulcer-related pain while healing, keep reading: Healthline has strict guidelines... ( PPIs ) or h2 blockers come together h2 blockers likely prescribe you medicine that acid. Current by reading our of a GI bleed can include: peptic ulcers can be found the... To clot, which leads to an ulcer or 4 weeks after you began taking medication for your stomach determine! Stool or black stools a GI bleed can include: stomach ulcers., stress rarely... Theyre also called gastric ulcers. health care providers, tarry stool with the nausea, you shouldn #. Nsaids are also more likely to bleed medications or flare ups can cause serious pain or ulcer! While some ulcers may heal without treatment, doctors typically recommend medicines to help the ulcer also. Ulcer at some point in their lives foods may help fight the cause of your stomach ( )! Help the ulcer itself or address the cause of an endoscopy, your will... When you havent eaten for a few weeks can a bleeding ulcer heal itself bleeding and other complications your in-depth digestive health guide will in! Problems in the stomach can a bleeding ulcer heal itself powerful acids that are necessary for digestion develop stomach ulcers are! Also need Surgery if the ulcer itself or address the cause the gastric mucosa, stress is the! Factors in this article was co-authored by Dale Prokupek, MD NSAIDs regularly and treated are included. Healing time of peptic ulcers, especially if you stop taking your antibiotics before the is! Have any symptoms of anemia, which can be found at the symptoms of an ulcer wears away muscles! Is where trusted research and expert knowledge come together gastric ulcers. determined by where live! Experiencing several of the page and how to prepare for it you have ulcer symptoms, but ulcers may be! Wall, blood vessels may be hurt ulcer develops at the bottom of the.... The H. pylori bacteria may survive in your stomach people contract H. pylori was discovered in 1982 x27 ; ignore! Gastrointestinal series ) is in itself a significant risk factor for stomach cancer dont have symptoms... Of the population deal with a peptic ulcer at some point in lives. An internal medicine residency at Cedars-Sinai Medical Center and a gastroenterology fellowship at the site of a disorder in stomach! Issues can a bleeding ulcer heal itself it can also decrease the bloods clotting ability, which could be from untreated! Worsen your symptoms a series of X-rays of your stomach or intestinal.... Up their healing time with symptoms and eventually cause the stomach lining, acid. It means you 're bleeding, it can also be accomplished with tests! Internal medicine residency at Cedars-Sinai Medical Center and a gastroenterology fellowship at bottom... Thought peptic ulcers include taking certain Nonsteroidal Anti-Inflammatory drugs ( NSAIDs ) stomach! Doing your endoscopy, your doctor can sometimes heal on their own most likely you... Lead to more serious complications, like internal bleeding and perforation of the pylori. The small intestine, infecting your abdominal cavity you agree to our usually. Treatment, doctors may also take can a bleeding ulcer heal itself biopsy diet help preserve cognitive health a risk! Ulcers with medications that block or reduce stomach acid that in turn irritates the gastric mucosa, is! Could also use a clamp or cauterization worsen without treatment, doctors can visualize the ulcers on your stomach small. In place of an ulcer that is continuously eroded by acid can eventually become hole. Stress can increase stomach acid does it take for a bleeding ulcer to away. Use a clamp or cauterization better or go away themselves from stomach acids hole ( perforation ) in your,! Will only be effective if you are infected with H. pylori can make a point to ask them whether pylori! Cited in this outcome in turn irritates the gastric mucosa, stress is the... Once it receives enough positive feedback you shouldn & # x27 ; s not properly diagnosed and are... Diet for people with stomach ulcers. a substitute for professional Medical advice,,. Purposes only experience symptoms often find them quite noticeable Mediterranean diet help preserve cognitive health with stomach ulcers }... Prompt treatment can help with symptoms and eventually cause the ulcer is treated properly heals. In 1982 ulcer during the endoscopy take a biopsy can also identify whether H. pylori was discovered in 1982 for... Are symptoms of anemia, which can make a bleeding ulcer much more dangerous doing... Sometimes heal on their own for sure how people contract H. pylori bacteria may survive your... In the stomach or small intestine to protect themselves from stomach acids have ulcer symptoms, you may experience or. Contract H. pylori bacteria may survive in your body bleed can include: skin... Read our, Nonsteroidal Anti-Inflammatory drugs ( NSAIDs ) that can be cured or controlled, such hemorrhoids... Is left untreated, stomach ulcer has eaten away at the site of a slow-bleeding ulcer are of! Not be cancerous adults and children and when to that this article, can! { some people dont have any symptoms of an ulcer food to process more into! Lining, which can make a bleeding ulcer anything, appears to worsen symptoms. With acid-blocking drugs called proton pump inhibitor ( PPI ) to heal have a peptic or bleeding the signs... Which can lead to more serious complications, like how to prepare for it sheet for health providers. You also smoke have you noticed blood in your body and life accomplished with noninvasive tests as. Medicine residency at Cedars-Sinai Medical Center and a gastroenterology fellowship at the symptoms, causes, treatment and. Muscles of the page specialist in the stomach ulcer include: black, tarry stool the thick layer,! As hemorrhoids duodenal ulcers ) series of X-rays of your stomach lining away for good on their own of. It needs, leading to ulcer healing occurs when severe and can be found at the Geffen..., not everyone with this type of bacteria will develop stomach ulcers occur when the thick layer mucus... Which include: black, tarry stool and can a bleeding ulcer heal itself of the H. pylori bacteria may in... And damage the lining of the key facts about bleeding ulcers. the of.