14 Common Causes of Internal Bleeding

2 . Certain Medications

Some medicines can raise your risk of internal bleeding because they affect how your blood clots or weaken the protective lining of your stomach. Blood thinners, also called anticoagulants and antiplatelet drugs, slow clot formation. Doctors use them to help prevent strokes, heart attacks, and blood clots. When clotting slows, even a small injury inside your body may bleed longer than usual.

The risk is higher in older adults, people with kidney problems, and those who take more than one blood-thinning medicine. Alcohol can increase this risk further by interfering with normal clotting. Warning signs may include blood in your urine, black or bloody stools, severe bruising, vomiting blood, or long nosebleeds. Other medicines increase bleeding risk in a different way.

Nonsteroidal anti-inflammatory drugs, often used for pain and swelling, can irritate and gradually damage the stomach lining. Over time, this may lead to ulcers that bleed inside your digestive tract. Alcohol can also add to stomach irritation and further increase the chance of bleeding.

3. Disease

Certain diseases can cause internal bleeding by damaging blood vessels or affecting the body’s ability to stop bleeding normally. You may not notice the bleeding at first because it happens inside your body.

Bleeding disorders are one cause because they affect how blood forms clots. If you have a disorder such as hemophilia or von Willebrand disease, bleeding may continue longer than normal after an injury and can occur in your joints, muscles, or organs.

Liver disease can also raise your risk because your liver makes proteins needed for clotting. When the liver does not work well, your body may not produce enough of these proteins, which makes bleeding more likely. This can lead to bleeding in your stomach or intestines.

Blood cancers can also interfere with normal clotting by lowering your platelet count. Platelets help stop bleeding, so when levels drop too low, you may bleed more easily inside your body even without a clear injury.

Stomach ulcers and other digestive diseases increase risk in a different way. They damage the lining of your stomach or intestines. When this lining breaks down, nearby blood vessels can tear and bleed. You might notice black stools, weakness, or vomiting blood.

4. Trauma

Trauma is a leading cause of internal bleeding because a hard blow, fall, or crash can tear blood vessels inside your body. The skin may look normal even when bleeding continues under the surface. Blunt force injuries often damage internal organs such as the liver, spleen, lungs, or brain. A car accident, sports injury, or physical assault can cause this type of harm. A strong hit to your head can also cause bleeding inside the skull, which raises pressure on your brain.

Penetrating injuries cause bleeding in a different way because they break through the skin and reach deeper tissues. Stab wounds and gunshot wounds are common examples. These injuries can cut large blood vessels and lead to rapid blood loss inside your chest or abdomen. If you take blood-thinning medicine or have a bleeding disorder, even minor trauma can cause serious internal bleeding.

Internal bleeding may develop slowly or progress quickly depending on the injury, so warning signs do not always appear right away. Severe pain in one area, swelling or tightness in the abdomen, deep purple bruising, dizziness, fainting, shortness of breath, weakness, or confusion may occur. Heavy blood loss can lead to shock because falling blood pressure reduces oxygen delivery to your organs.

5. Aneurysms

An aneurysm is a weak spot in the wall of an artery. Over time, the pressure of blood flow can cause this weak area to bulge outward. Many aneurysms stay small and cause no symptoms for years. Most aneurysms form in the aorta, the main artery that carries blood from your heart through your chest and abdomen.

They can also develop in arteries in your brain. As they enlarge, they may begin to press on nearby tissues. Larger aneurysms can cause pain in your chest, back, or abdomen. A brain aneurysm may cause headaches, vision changes, or nerve problems before it ruptures. If the weakened wall ruptures, it can lead to sudden and severe internal bleeding.

When a brain aneurysm ruptures, blood collects inside the skull and can quickly become life threatening. Blood can also leak between layers of the artery wall or spill into nearby spaces in your body. This loss of blood flow can lead to shock, stroke, or organ damage. High blood pressure, smoking, hardening of the arteries, and a family history of aneurysms can increase risk.

6. Broken Bones

A broken bone can lead to internal bleeding, especially after a hard fall or crash. When a bone breaks, sharp edges can tear nearby blood vessels, allowing blood to collect beneath the skin or within deeper tissues. Some fractures carry a higher risk because they involve larger vessels or nearby organs.

Pelvic fractures and thigh bone fractures can cause major blood loss because these areas contain large blood vessels. Rib fractures can injure the lungs or nearby vessels and lead to bleeding in the chest. Skull fractures can also cause bleeding around the brain. You may not always see clear signs at first. Pain, swelling, and deep bruising often appear near the injury. The area may feel firm or tight as blood builds up within muscle or surrounding tissues.

As blood loss increases, you may notice weakness, dizziness, pale skin, a fast heartbeat, or fainting. Shortness of breath or confusion can also occur. Open fractures, where bone pushes through the skin, can cause both external and internal bleeding. Even closed fractures may bleed heavily, so severe pain after trauma should raise concern for hidden bleeding.

7. Surgery

Surgery can cause internal bleeding because it involves cutting through skin, tissue, and sometimes organs. Even when a surgeon works carefully, blood vessels may continue leaking during or after the procedure. Small amounts of bleeding are common, but heavier blood loss can become serious. The risk is higher when surgery involves major organs such as the liver, spleen, or large blood vessels.

Operations in the abdomen, chest, pelvis, or brain can also lead to hidden bleeding because blood can collect inside the body without clear signs at first. Taking blood-thinning medications, having a bleeding disorder, or developing clotting problems after surgery can make bleeding harder to stop.

Infections at the surgical site can also damage nearby tissue and increase bleeding risk. As blood loss continues, warning signs may include swelling, severe pain, bruising around the surgical area, weakness, dizziness, faintness, or a drop in blood pressure. In severe cases, internal bleeding can lead to shock, which requires emergency care.

8. Kidney Disease

Kidney disease can lead to internal bleeding, especially in your urinary tract. Your kidneys filter waste from your blood, and when they become damaged, they cannot work as they should. Chronic kidney disease often develops slowly, with diabetes and high blood pressure among the most common causes. Over time, damaged kidneys can interfere with normal clotting, which raises your risk of bleeding.

Some people with kidney failure need dialysis to clean their blood. Because dialysis may require blood thinners, it can further increase bleeding risk. Certain kidney conditions can also trigger bleeding more directly. These include kidney infections, kidney stones, inflammation of the kidney filters, and advanced kidney failure.

When bleeding occurs, you may notice blood in your urine. It can appear pink, red, or brown. In some cases, the bleeding is small and only shows up on a lab test. Severe kidney disease may also lower your red blood cell count, which can make you feel weak or tired. If waste builds up in your blood, it can affect many organs.

9. Stomach Ulcers

A stomach ulcer is a sore in the lining of your stomach. It develops when stomach acid damages the inner layer and gradually forms an open area in the tissue. If the ulcer extends deeper, it can break into a blood vessel and cause internal bleeding. The most common causes include infection with Helicobacter pylori bacteria and long-term use of nonsteroidal anti-inflammatory drugs.

These pain relievers reduce the stomach’s protective defenses over time. Smoking and heavy alcohol use can also raise your risk. You may feel a burning or dull pain in your upper belly. The pain often starts between meals or at night and may ease for a short time after you eat or take antacids.

When bleeding occurs, you may notice black or tar-like stools. You might also vomit blood that looks red or dark brown. Some people feel weak, dizzy, or short of breath because of blood loss. Doctors often begin with breath, blood, or stool tests to look for infection. They may also use an endoscopy, which lets them view your stomach with a small camera.

10. Gastrointestinal Conditions

Gastrointestinal conditions affect your digestive tract, which includes your esophagus, stomach, small intestine, and large intestine. When bleeding develops inside this tract, it may remain hidden at first and become serious as blood loss continues.

Several common conditions can cause this type of internal bleeding. These include stomach or duodenal ulcers, inflammation of the stomach or esophagus, enlarged veins in the esophagus or stomach, Crohn disease or ulcerative colitis, diverticulosis, colon or stomach cancer, and hemorrhoids or anal fissures. Some causes, such as hemorrhoids, are usually mild.

Others, including ulcers, enlarged veins, or cancer, can lead to greater blood loss. You might notice black, tarry stools or bright red blood in your stool. You may also vomit blood or material that looks like coffee grounds. These signs often point to bleeding in the upper part of your digestive system. Even slow bleeding over time can lower your red blood cell count and cause anemia, which may leave you feeling weak, tired, or dizzy.

11. Ruptured Cysts

A cyst is a closed sac in your body that can fill with fluid, air, or other material. Many cysts are harmless, but some can rupture and lead to internal bleeding. This often occurs in areas such as the ovaries, kidneys, liver, or spleen. Trauma, infection, or rapid growth can increase the risk. If a cyst presses on nearby blood vessels before it opens, blood loss may become more likely.

When this happens, fluid and blood can leak into nearby tissue. You may feel sudden pain in the affected area, and the pain can range from mild to severe. Ovarian cysts are a common example. If one ruptures, you may notice sharp lower belly pain, bloating, or lightheadedness.

In some cases, bleeding inside the abdomen becomes heavy enough to cause weakness or fainting. Cysts in solid organs such as the liver or kidneys can also bleed if they tear. Warning signs include sudden severe pain, swelling in the abdomen, dizziness, pale skin, a fast heartbeat, or fainting.

12. Endometriosis

Endometriosis happens when tissue similar to the lining of your uterus grows outside of it. This tissue can attach to your ovaries, fallopian tubes, bowel, bladder, or other areas in your pelvis. Like the uterine lining, it thickens and bleeds during your menstrual cycle. Because the blood remains trapped in the pelvic area, it can cause swelling and irritation over time.

Repeated irritation may also lead to scar tissue, which can make nearby organs stick together and increase pressure inside your abdomen. You may notice heavy periods, bleeding between periods, or severe menstrual cramps. Some people also feel pain during sex, bowel movements, or urination.

In some cases, ongoing inflammation can affect your ability to get pregnant. The exact cause of endometriosis is not fully known. Hormones, genetics, and problems with menstrual flow may all play a role. Treatment often includes hormonal therapy, nonsteroidal anti-inflammatory drugs for pain, or surgery to remove areas of abnormal tissue.

13. Tuberculosis

Tuberculosis is a bacterial infection that often affects your lungs. It spreads through the air when a person with active disease coughs or speaks. Once inside your body, the bacteria can multiply and injure lung tissue. When tuberculosis involves your lungs, the infection can damage small blood vessels in the airways.

This may cause a cough that lasts more than three weeks, and you may cough up mucus mixed with blood. You might also notice chest pain, fever, night sweats, weight loss, and fatigue. If the bacteria spread beyond your lungs, they can affect your kidneys, spine, or brain. In rare cases, bleeding can occur in these areas when the infection becomes severe.

Doctors use skin tests or blood tests to check for infection. A chest X-ray and lab tests of your sputum help confirm active disease. Without treatment, tuberculosis can worsen and may become life threatening. Treatment requires a combination of antibiotic medications taken for several months. You need to take every dose as directed to fully clear the infection and prevent drug resistance.

14. Blood Thinners

Blood thinners are medicines that lower your blood’s ability to form clots. Doctors prescribe them to help prevent heart attacks, strokes, and clots in the legs or lungs. These drugs do not remove a clot, but they can stop it from getting larger. You may take an anticoagulant or an antiplatelet drug.

Anticoagulants slow clot formation, while antiplatelet drugs prevent blood cells called platelets from sticking together. Because these medicines make bleeding harder to stop, even a small injury inside your body can bleed longer than normal. Your risk is higher if you are older, have kidney problems, or take other medicines that affect clotting.

Blood thinners can cause internal bleeding in areas such as the stomach, intestines, brain, or urinary tract. In the digestive tract, bleeding may cause red or black stools. In the brain, it may cause a sudden headache, weakness, or trouble speaking.