How Do You Know If You Have a Bleeding Ulcer?

A bleeding ulcer announces itself in several ways, but the most recognizable sign is a change in what comes out of your body: vomiting material that looks like coffee grounds, or passing stools that are black, sticky, and unusually foul-smelling. Those two symptoms point strongly toward an ulcer that has eroded into a blood vessel in the stomach or upper small intestine. Not every bleeding ulcer is that obvious, though. Some bleed so slowly that you never see blood at all and only discover the problem when fatigue, dizziness, or unexplained anemia sends you to a doctor.

The Symptoms You Can See

When an ulcer bleeds briskly, the blood either travels upward or downward through the digestive tract, and each direction produces a different visible clue. Blood that comes up as vomit usually looks dark and granular, often compared to coffee grounds, because stomach acid partially digests the hemoglobin before it reaches your mouth. If the bleeding is fast enough, the vomit can be bright red instead. Blood that moves downward through the intestines gets chemically altered along the way, turning stool jet black and tarry. Doctors call this melena, and it has a distinctively strong odor that most people notice right away. Acute upper gastrointestinal bleeding is a common emergency, carrying hospital mortality above 10%, with peptic ulcers being one of the leading causes.¹

Either of those signs, coffee-ground vomit or black tarry stool, warrants urgent medical attention. Bright red blood in the stool is less commonly from an ulcer and more often originates lower in the digestive tract, though a massively bleeding stomach ulcer can produce red stool if the blood is moving through quickly enough. The key distinction is color and texture: tarry and black points upward, bright red usually points downward.

When Bleeding Is Invisible

Not all bleeding ulcers produce dramatic symptoms. Chronic or occult gastrointestinal bleeding is not apparent to the patient and usually shows up as a positive fecal occult blood test or iron deficiency anemia found on routine bloodwork.² You lose a small amount of blood each day, your body’s iron stores gradually deplete, and eventually you feel tired, short of breath during mild exertion, or lightheaded when standing up.

In rare cases, the anemia becomes severe enough to cause fainting before anyone suspects a GI source. One published case described a teenager admitted after a week of worsening fatigue and pallor with no stomach complaints at all; she had fainted four times in three days. Investigation revealed iron deficiency anemia from a chronically bleeding, inflamed stomach lining.³ That scenario is unusual, but it illustrates how quietly a bleeding ulcer can operate. If you develop unexplained anemia or persistent fatigue, the possibility of slow GI blood loss is worth raising with your doctor, even if your stomach feels fine.

Why Ulcers Start Bleeding

An ulcer bleeds when it erodes deep enough to reach a blood vessel in the stomach or duodenal wall. Small vessels produce slow oozing; larger arteries produce sudden, heavy hemorrhage.⁴ The two biggest risk factors for developing a peptic ulcer in the first place, and for that ulcer eventually bleeding, are infection with the bacterium Helicobacter pylori and the use of nonsteroidal anti-inflammatory drugs such as ibuprofen, naproxen, and aspirin. Left untreated, peptic ulcer disease leads to major complications like hemorrhage, perforation, or obstruction in roughly 20 to 25 percent of patients, and upper GI bleeding accounts for about 70 percent of those complications.⁵

NSAIDs damage the stomach lining through multiple pathways: they irritate the surface directly, suppress protective mucus production, reduce blood flow to the stomach wall, and interfere with the lining’s ability to repair itself.⁶ The resulting injury can progress from inflammation to a frank ulcer that eventually erodes into a vessel. This is why long-term NSAID use, especially in older adults or people taking blood thinners simultaneously, carries a meaningful risk of ulcer bleeding.⁷

Medications That Raise the Risk Beyond NSAIDs

Certain antidepressants also deserve mention. Selective serotonin reuptake inhibitors and related drugs affect platelet function because platelets rely on serotonin to help form clots. When someone takes an SSRI alongside blood thinners or antiplatelet medications, the combined effect on clotting can tip the balance toward bleeding. A meta-analysis of over a dozen studies found that people on anticoagulant therapy who also used serotonin reuptake inhibitors had about 39 percent higher odds of major bleeding compared to those not taking the antidepressants.⁸ A separate study found that SSRI use alone roughly doubled the risk of upper GI bleeding, and using SSRIs together with NSAIDs pushed the risk even higher.⁹

This does not mean you should stop your antidepressant out of fear. The absolute risk of a GI bleed from an SSRI alone remains low for most people. But if you are on a combination of an SSRI, an NSAID, and a blood thinner, the layered effect on bleeding risk is something worth discussing with whoever prescribes your medications.

How Doctors Confirm the Diagnosis

If your symptoms suggest a bleeding ulcer, the first step in the emergency department is stabilization: intravenous fluids, blood tests to check your hemoglobin and kidney function, and sometimes a blood transfusion. After that, the gold-standard diagnostic tool is an upper endoscopy, in which a flexible camera is guided through your mouth into the stomach and duodenum. Carefully performed endoscopy provides an accurate diagnosis of the bleeding source and identifies high-risk features that determine whether treatment can be applied on the spot.¹⁰

For more subtle or chronic bleeding, the workup may start with simpler tests. A fecal occult blood test checks for hidden blood in a stool sample, and blood work revealing iron deficiency anemia in the absence of another explanation strongly suggests chronic GI blood loss. Doctors also look at the ratio between blood urea nitrogen and creatinine in your blood. When you bleed into the upper GI tract, your intestines digest the blood’s protein and reabsorb it, pushing urea levels up. A meta-analysis found that this ratio is meaningfully higher in upper GI bleeding than in lower GI bleeding, and at an optimal cutoff it had moderate accuracy for distinguishing between the two.¹¹ It is not precise enough to replace endoscopy, but it helps guide early decision-making in the emergency room.

In cases where standard endoscopy does not find the source, capsule endoscopy is sometimes used. You swallow a pill-sized camera that photographs the intestine as it passes through. This approach has higher sensitivity than CT scanning or push enteroscopy for finding obscure bleeding sources, though it is less specific.¹²

What Doctors See During Endoscopy and Why It Matters

When the endoscope reaches the ulcer, the appearance of the bleeding site tells doctors a great deal about what to expect next. Gastroenterologists classify what they see using a system called the Forrest classification, which still has predictive value for rebleeding risk.¹³ At one extreme is an ulcer with an actively spurting artery, which carries the highest risk of continued or recurrent bleeding. At the other extreme is a clean-based ulcer with no visible vessel or clot, which rarely rebleeds.

The distinction has real consequences for treatment decisions. In one large international trial, patients with spurting arterial bleeding who received only a placebo after endoscopic treatment had a rebleeding rate of about 22.5 percent over 72 hours. Those with oozing bleeding, by contrast, rebled less than 5 percent of the time, a rate low enough that aggressive intervention beyond the initial endoscopy added little benefit.¹⁴ The practical takeaway is that not all bleeding ulcers require the same level of intervention. What the ulcer looks like under the camera helps determine how aggressively doctors need to act.

Hospitals also use scoring tools before endoscopy to triage patients. The Glasgow-Blatchford Score combines factors like hemoglobin, blood pressure, heart rate, and whether you presented with blood in your vomit or stool. Higher scores predict a greater need for intervention. One study found that implementing a fast-track protocol for patients with the highest scores cut the time from arrival to endoscopy nearly in half and reduced blood transfusion requirements substantially.¹⁵ Patients with low scores, on the other hand, can sometimes be managed without emergency endoscopy at all and may even be candidates for outpatient follow-up.¹⁶

How a Bleeding Ulcer Is Treated

Treatment typically happens in two layers: stopping the active bleed and then preventing it from starting again. During endoscopy, the doctor can apply therapy directly to the bleeding site. The most common techniques include metal clips that physically clamp the vessel shut, injection of a solution like epinephrine to constrict the vessel and slow blood flow, and thermal probes that cauterize the tissue.¹⁷ Often doctors combine two of these methods for higher-risk ulcers.

After endoscopy, the second layer of treatment involves acid suppression with proton pump inhibitors such as omeprazole or pantoprazole. Stomach acid interferes with clot formation. At a pH below about 5.4, the acid activates an enzyme that breaks down the platelet plugs your body is trying to form over the wound. By suppressing acid production aggressively, typically with an intravenous infusion for the first 72 hours, doctors give the clot time to stabilize and the ulcer time to begin healing.¹⁸ After discharge, oral proton pump inhibitors are typically continued for six to eight weeks to allow the ulcer to fully heal.¹⁹

If H. pylori testing comes back positive, eradication therapy with a combination of antibiotics and a proton pump inhibitor is critical. Clearing the infection dramatically reduces the chance of the ulcer returning. If NSAIDs caused the ulcer, the obvious step is to stop them or switch to a less harmful alternative, though for people who cannot avoid NSAIDs, adding a daily proton pump inhibitor for protection is standard practice.

Rebleeding and Long-Term Outlook

One of the underappreciated realities of bleeding ulcers is that they tend to come back. Among patients whose ulcer has both perforated and bled, the risk of rebleeding within one to two years is about 33 percent. Over a full decade, that figure climbs to 40 to 50 percent.¹⁹ Those numbers are highest in people who continue the behaviors or exposures that caused the original ulcer, whether that is ongoing NSAID use, untreated H. pylori, or heavy alcohol intake.

Alcohol’s relationship to ulcer bleeding is worth understanding. A large prospective study of men found that consuming roughly two or more standard drinks a day was associated with a higher risk of major GI bleeding, and the risk climbed further when heavy drinking was combined with NSAID or aspirin use. Men who drank at least 15 grams of alcohol per day and also used NSAIDs or aspirin had about 75 percent higher risk than nondrinkers.²⁰ Interestingly, smoking was not independently linked to GI bleeding in that same study, despite its well-known role in delaying ulcer healing.

Other Conditions That Can Look Like a Bleeding Ulcer

Several other conditions mimic bleeding-ulcer symptoms closely enough to cause confusion before endoscopy sorts things out. Mallory-Weiss tears, which are small rips in the lining where the esophagus meets the stomach, typically occur after forceful vomiting or retching and produce bright red blood in the vomit. Dieulafoy lesions are abnormally large arteries sitting just beneath a normal-looking stomach surface that can rupture without any ulcer being present. Esophageal varices, swollen veins in the esophagus linked to liver disease, produce heavy bleeding that can look identical to an ulcer bleed. In patients with advanced liver disease, distinguishing between these sources before endoscopy is difficult.²¹

Stomach cancer can also present with bleeding and may look similar to an ulcer on initial inspection. This is one reason endoscopists routinely biopsy suspicious-looking ulcers, particularly gastric ulcers in older patients or ulcers that do not heal with standard treatment. The symptom overlap means you should not try to self-diagnose based on symptoms alone; the same dark stool or vomited blood could stem from several different problems, each requiring different treatment.

Stress Ulcers in Hospitalized Patients

A distinct category worth knowing about is the stress ulcer, which develops not from NSAIDs or H. pylori but from the physiological strain of a severe illness, major surgery, or extensive burns. These ulcers have been documented since the 1800s and are a recognized complication in critically ill patients in intensive care units.²² Patients on mechanical ventilators or those with clotting disorders are at highest risk. In ICU settings, prophylactic acid-suppression therapy is often given to prevent these ulcers from forming in the first place.

Stress ulcers are not the same thing as an ulcer caused by emotional stress. Everyday psychological stress has not been convincingly shown to cause peptic ulcers on its own, though it may worsen symptoms in someone who already has one. The “stress ulcers” that develop in ICU patients arise from reduced blood flow to the stomach lining during critical illness, a different mechanism entirely from the H. pylori or NSAID pathway.

When to Seek Emergency Care

If you vomit anything that looks like blood or coffee grounds, or if your stools turn black and tarry, go to the emergency room. Do not wait to see if it resolves on its own. The same applies if you feel suddenly dizzy, lightheaded, or faint alongside abdominal pain, especially if you take NSAIDs, blood thinners, or have a history of ulcers. Rapid blood loss can cause your blood pressure to drop quickly, and delay in treatment worsens outcomes.

For subtler presentations, pay attention to persistent fatigue that does not improve with rest, shortness of breath during activities that used to be easy, or a pale complexion that others comment on. These are signs of chronic anemia, and while many things can cause anemia, a slow-bleeding ulcer belongs on the list. A simple blood count and stool test at your doctor’s office can rule it in or out without an emergency visit, but the conversation is worth initiating rather than waiting for something more dramatic to happen.