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10 Things That Can Cause Blood in Your Urine

There are some pretty surprising offenders here.
blood spots in the toilet bowl
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Not sure if you’ve realized, but you and peeing are in an extremely committed relationship. You’ve been doing it since you were born, after all, which means you have a solid idea of what your pee should look like. Seeing blood in your urine doesn’t exactly make the cut.

“Blood in your urine can be alarming,” Jennifer Linehan, M.D., urologist and associate professor of urologic oncology at the John Wayne Cancer Institute at Providence Saint John’s Health Center in Santa Monica, California, tells SELF. Gross hematuria, which is blood that you can see in your urine, might make your pee look pink, red, or like you dumped some Coke into the toilet, according to the Mayo Clinic. Microscopic hematuria is blood in your pee that’s only visible under a microscope. None of this is ideal, but some causes of bloody urine are more serious than others. Here’s what could be behind your bloody pee.

1. You ate something hella red.

Let’s start with the least worrisome cause: You might not actually be seeing blood at all. Foods with deep red hues such as beets, rhubarb, and berries can make your pee look red, according to the Mayo Clinic. This will typically go away within a few days, but it’s smart to see your doctor anyway just to be certain your red pee is, in fact, food-related.

2. You have a bladder infection.

A bladder infection is a type of urinary tract infection that happens when bacteria gets into your body through your urethra (the small opening through which you pee). There, the bacteria can multiply, causing symptoms like a constant urge to pee, pain and burning when you do manage to squirt any out, and pelvic pressure, the Mayo Clinic explains.

This kind of UTI can inflame the lining of your bladder enough for it to bleed and result in bloody urine, Tom Guzzo, M.D., chief of urology at Penn Medicine, tells SELF. “It’s almost like having tiny cuts or a rash on the inside of the bladder,” Dr. Linehan adds.

See your doctor if you have any symptoms of a bladder infection. They’ll likely test your urine and, if you do have an infection, prescribe antibiotics to help get rid of it, according to the U.S. National Library of Medicine. Without prompt treatment, your bladder infection can progress to a kidney infection, so don’t try to push through it.

3. You have a kidney infection.

Speaking of bladder infections progressing, a kidney infection is a type of UTI that starts in your bladder and moves up to one or both of your kidneys, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) says. (Your kidneys filter your blood and remove waste and extra water, which become urine, the U.S. National Library of Medicine explains.)

Kidney infections share a few symptoms with bladder infections, including frequent, painful peeing and bloody urine (like a bladder infection, this is due to irritation and inflammation in your urinary tract, Doreen Chung, M.D., a urologist at NewYork-Presbyterian/Columbia University Irving Medical Center, tells SELF). They can also cause chills, fever, nausea, vomiting, and back, side, or groin pain, the NIDDK says.

If you suspect you have a kidney infection, see your doctor ASAP. They’ll likely want to put you on antibiotics. If your case is severe, you may need to be hospitalized so you can receive IV antibiotics and fluids, the Mayo Clinic says. Like a bladder infection, you don’t want to wait this out: A kidney infection can permanently damage your kidneys, or in severe cases, the bacteria can spread to your bloodstream and cause a life-threatening infection, the Mayo Clinic says.

4. You have a bladder or kidney stone.

Fun fact about your pee: It contains minerals. But if your urine is too concentrated, those minerals can form crystals on the walls of your kidneys or bladder, the Mayo Clinic says, and eventually transform into small, hard stones. You can have bladder or kidney stones that you might not even know about because they don’t cause symptoms. Or they can lead to a ton of pain, along with red flags like bloody pee.

This might happen when your body tries to pass a stone by peeing it out or if a stone blocks part of your urinary tract. Stones (and especially kidney stones) can cause sharp pains in your back, groin, side, or lower abdomen, a constant need to pee even though nothing comes out when you try, pain when you pee, cloudy or bad-smelling urine, and pink, brown, or red pee due to blood, the NIDDK says. This is because stones can create micro-scratches in the lining of your urinary tract, Dr. Linehan says.

Your treatment will depend on the size, shape, and location of your stone, the NIDDK says. In most cases, even if the process really hurts, you’ll be able to pass the stone through your pee. If you have a larger stone, though, your doctor can use shock waves to smash it into smaller pieces so you can pee them out, the NIDDK explains. Your doctor may also insert long, thin tools into your urethra to locate the stone, then remove it or break it into smaller pieces. In some cases, you may need to have a special medical instrument inserted into your kidney to remove the stone, but that’s really a last resort.

5. Your kidneys are inflamed.

Microscopic or visible blood in your pee is a common sign of glomerulonephritis, which is when your kidneys' filtering system becomes inflamed, according to the Mayo Clinic. This may happen as a side effect of a systemic disease that can damage your kidneys, like type 1 or type 2 diabetes. (Poorly controlled high blood sugar can lead to high blood pressure, which can overly tax your kidneys’ filtering system, the Mayo Clinic explains.) It can also come about due to something like a viral infection, or it can happen for no real reason.

Since this condition causes the filters in your kidney to work less efficiently, that can allow blood into your urine, Dr. Chung says. You might also experience symptoms like foamy pee because it contains too much protein, high blood pressure, and bloating in your face, hands, feet, and abdomen, the Mayo Clinic explains.

Treatment for glomerulonephritis depends on factors like the underlying cause and severity of your symptoms. It might resolve without treatment, particularly if it’s due to something like a strep infection that inflames your kidneys. But if it’s due to an illness like diabetes, your treatment plan might need tweaking.

6. You have sickle cell anemia.

There are two main genetic disorders that can cause both visible and microscopic blood in your pee, the Mayo Clinic says. Sickle cell anemia is one of them. This inherited condition damages the hemoglobin in your red blood cells, which is responsible for transporting oxygen in your blood.

If you have sickle cell anemia, your typically round red blood cells are instead crescent-shaped like those farming tools called sickles. They can then block your blood from flowing properly, potentially forcing it to come out in your urine, Dr. Chung explains. Beyond bloody urine, sickle cell anemia can cause a lot of pain (which can be so bad it might require hospitalization), frequent infections, vision issues, and swelling of the hands and feet among other issues, the Mayo Clinic says.

Your doctor can treat sickle cell anemia with a variety of medications, including antibiotics to ward off life-threatening infections, pain-relieving medications, and hydroxyurea, a medication that can prevent episodes of pain, the Mayo Clinic says. A bone marrow transplant is the only potential cure for this condition—otherwise, managing it will be a lifelong endeavor.

7. You have Alport syndrome.

Alport syndrome, which messes with the filtering membranes in your kidneys’ small blood vessels, is the other main inherited syndrome that can lead to visible or microscopic blood in your pee through glomerulonephritis. It can also cause issues like full-body swelling, high blood pressure, pain in your flank (the part of your body between your upper stomach and back), hearing loss, and eye problems.

With Alport syndrome, your doctor may recommend eating a diet that’s low in salt and potassium (it’s hard for your body to process these properly if your kidneys aren’t functioning well), taking medication to slow kidney damage, and taking medicine to control your blood pressure if hypertension is an issue for you, according to the U.S. National Library of Medicine.

8. Your medication is causing bloody pee.

Turns out some drugs can allow blood to seep into your urine, including penicillin, nonsteroidal anti-inflammatory pain relievers, and the anti-cancer medicine cyclophosphamide, the Mayo Clinic says. If you happen to have a condition that causes your bladder to bleed (like a UTI) and you take a blood thinner such as aspirin, you might also notice blood in your urine.

If you’re seeing bloody pee and you suspect your medication is to blame, you should get this checked out just as urgently as you would if you weren’t on one of these medications, Dr. Guzzo said. While it could be due to your medication, it could also be due to a separate health issue that’s developing as you take a certain drug, so it’s worth finding out exactly what the deal is.

9. You went way too hard at the gym.

This is rare (and kind of bonkers), but sometimes exercising really hard can cause blood in your pee, according to the Mayo Clinic. Doctors aren’t totally sure why this happens, but one theory is that exercise can distress your bladder enough for it to bleed. Another is that you’re peeing out some red blood cells that broke down due to exertion. (This is normal if you do intense aerobic exercise for an extended period of time, according to the Mayo Clinic.)

Runners are the most likely to develop exercise-induced hematuria, but anyone can get it after a really hard workout. It typically just goes away after a few days, Dr. Guzzo says, but you should still see a doctor ASAP to make sure nothing more serious is to blame.

10. Rarely, bloody pee can be a sign you have cancer.

If you have blood in your urine, it’s much more likely that it’s due to something like a urinary tract infection than cancer. But certain advanced cancers, like those of the kidney and bladder, can cause visible blood in your urine, the Mayo Clinic says. The tumor itself can bleed, or sometimes it causes irritation or inflammation that can prompt bleeding, Dr. Chung says. These cancers sometimes cause other symptoms, such as painful urination, pain in your back, side, or pelvis, and fatigue—all pretty nondescript and easy to mistakenly chalk up to other causes.

We repeat: If you notice blood in your urine, it’s probably not due to cancer. But the mere possibility is still one of the reasons why it’s so important to get bloody urine checked out, no matter which other symptoms you are (or aren’t) experiencing.

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