Persistent or recurring bleeding usually points to one of a handful of causes: a hormonal imbalance, a medication side effect, a structural problem in the body, or less commonly, an underlying clotting disorder. The right answer depends on where you’re bleeding, how often, and how much. This guide walks through the most likely explanations so you can start narrowing down what’s going on.
Heavy or Irregular Periods
For many people searching this question, the bleeding they’re concerned about is menstrual, or at least seems to be. Heavy periods, bleeding between periods, or cycles that drag on for weeks all fall under what doctors call abnormal uterine bleeding. The causes are split into two broad categories: structural problems in the uterus and non-structural issues like hormonal shifts or clotting problems.
Structural causes include polyps (small growths on the uterine lining), fibroids (noncancerous muscle tumors in the uterine wall), and, rarely, precancerous or cancerous changes. These tend to cause predictable patterns of heavy flow or spotting between periods.
Non-structural causes are more common in younger people. The biggest one is ovulatory dysfunction, where your body doesn’t release an egg during a cycle. Without ovulation, progesterone levels stay low, and the uterine lining keeps thickening under the influence of estrogen alone. Eventually, the lining sheds irregularly and unpredictably, often heavily. This is especially common during the teen years, during perimenopause, in people with polycystic ovary syndrome (PCOS), and during periods of significant stress or weight change.
If you’ve gone through menopause and are experiencing bleeding again, that warrants prompt evaluation. Roughly 9% of postmenopausal women who see a doctor for unexpected bleeding are eventually diagnosed with endometrial cancer. That means the vast majority have a benign cause, but the odds are high enough that it should always be checked.
Medications That Increase Bleeding
Some of the most widely used over-the-counter and prescription drugs make bleeding worse or harder to stop. If you’re taking any of the following, that may be your answer:
- Pain relievers like ibuprofen (Advil, Motrin) and naproxen (Aleve): These belong to a class of anti-inflammatory drugs that interfere with platelet function, making it harder for blood to clot. Even occasional use can increase bleeding, and regular use raises the risk further.
- Aspirin: Even low-dose “baby aspirin” (81 mg) reduces your blood’s ability to form clots. This effect lasts for days after a single dose.
- Blood thinners like warfarin (Coumadin) or newer anticoagulants: These are prescribed specifically to prevent clotting, so increased bleeding is an expected trade-off. Nosebleeds, heavy periods, bleeding gums, and easy bruising are all common.
- Antidepressants (SSRIs): Selective serotonin reuptake inhibitors can reduce platelet clumping, which may lead to easier bruising or heavier menstrual flow.
If you suspect a medication is behind your bleeding, don’t stop taking it without guidance from whoever prescribed it. But do bring it up, because dosage adjustments or alternatives may help.
Nosebleeds That Keep Coming Back
Recurrent nosebleeds are one of the most common reasons people wonder why they keep bleeding. The most frequent culprit is simple: dry air. Low humidity, heated indoor spaces, and high altitudes all dry out the delicate tissue inside your nose, making it crack and bleed easily. Nose picking, frequent nose blowing during colds or allergies, and overuse of decongestant nasal sprays compound the problem.
A humidifier, saline nasal spray, and a thin layer of petroleum jelly inside the nostrils can break the cycle for most people. If nosebleeds persist despite these measures, or if they’re heavy and hard to stop, systemic causes like high blood pressure, alcohol use, blood-thinning medications, or an inherited bleeding disorder may be involved.
Bleeding From the Digestive Tract
Blood in your stool or vomit points to gastrointestinal bleeding, which can be chronic and subtle or sudden and severe. Where the blood comes from determines what it looks like. Bright red blood on toilet paper or in the bowl usually comes from the lower digestive tract. Dark, tarry, or black stools suggest bleeding higher up, in the stomach or upper intestines.
Common causes of upper GI bleeding include peptic ulcers (often from long-term use of anti-inflammatory painkillers or an infection called H. pylori), chronic acid reflux that damages the esophagus, and esophageal varices in people with liver disease. Lower GI bleeding is frequently caused by hemorrhoids, diverticulosis (small pouches in the colon wall that can bleed), and inflammatory bowel diseases like ulcerative colitis or Crohn’s disease.
Chronic GI bleeding can be so gradual that you don’t notice blood at all. Instead, you feel tired, short of breath, or lightheaded from slow blood loss that drives down your red blood cell count over weeks or months.
Clotting Disorders
If you’ve always bruised easily, bled heavily with periods, had prolonged bleeding after dental work, or noticed that cuts take unusually long to stop, you may have an inherited bleeding disorder. The most common one is von Willebrand disease, which affects how well platelets stick together to form an initial clot.
Diagnosing von Willebrand disease takes multiple blood tests, and the results can fluctuate based on stress, illness, and hormonal changes. It often requires repeat testing before a clear diagnosis emerges. Many people with mild forms go undiagnosed for years, assuming their bleeding is normal because it’s all they’ve ever known.
Vitamin K deficiency is another, less common cause. Vitamin K is essential for activating several proteins in the clotting chain. Without enough of it, blood clots form slowly or incompletely. Adults need about 90 to 120 micrograms per day, which most people get from leafy green vegetables. Deficiency is rare in healthy adults but can develop in people with digestive conditions that impair fat absorption, since vitamin K is a fat-soluble vitamin.
Easy Bruising and Slow-Healing Cuts
Sometimes the concern isn’t a single bleeding site but a general pattern: bruises appearing from minor bumps, small cuts that ooze for a long time, or bleeding gums when brushing. This pattern can reflect low platelet counts, platelet dysfunction, or problems with the clotting proteins in your blood.
Platelet counts can drop from viral infections, autoimmune conditions, certain medications, heavy alcohol use, or bone marrow problems. When platelets are low or not working properly, you tend to see bleeding at the surface: skin bruises, gum bleeding, nosebleeds, and prolonged oozing from small wounds.
Problems with clotting proteins, on the other hand, tend to cause deeper bleeding into joints or muscles, or heavy bleeding after surgery or injury. This distinction can help point testing in the right direction.
Warning Signs of Serious Blood Loss
Most recurring bleeding is annoying but not dangerous. However, some situations need urgent attention. A rapid heart rate, dizziness when standing, pale or clammy skin, confusion, or fainting can all signal that you’ve lost enough blood to affect circulation. Black, tarry stools are a classic sign of significant upper GI bleeding and should be evaluated quickly, even if you feel fine otherwise, because internal bleeding can build for hours before symptoms become obvious.
Heavy menstrual bleeding that soaks through a pad or tampon every hour for several consecutive hours, or any bleeding episode you simply cannot get to stop with direct pressure, also warrants prompt care.
Getting to the Cause
The first step in figuring out recurring bleeding is usually a complete blood count, which reveals whether your red blood cells or platelets are low. If a clotting problem is suspected, additional tests measure how quickly your blood forms a clot. Normal clotting time is roughly 10 to 13 seconds for one standard test, with variations depending on the specific test used. Results outside that range point toward specific clotting factor deficiencies or medication effects.
From there, the workup depends on where the bleeding is happening. Abnormal uterine bleeding may call for an ultrasound or a biopsy of the uterine lining. GI bleeding typically requires an endoscopy or colonoscopy to find the source. Recurrent nosebleeds that resist basic treatment sometimes need an evaluation of the blood vessels inside the nose. In each case, the goal is the same: find the specific source and the underlying reason so that treatment targets the actual problem rather than just managing symptoms.