context: A catheter is a thin, flexible tube that can put fluids into your body or take them out. If you have trouble peeing or can't control when you pee, a urinary catheter that goes into your bladder can get rid of urine for you. If you need blood or medicine, your doctor might use an intravenous catheter that's connected to one of your veins with a needle. For example, if you had cancer and needed chemotherapy, that's how you'd get it. Depending on your health and how long you'll need help peeing, your doctor might recommend: Intermittent catheters. You use one of these several times a day, either at scheduled times or whenever your bladder feels full. It usually goes in through your urethra (the tube that takes urine from your bladder out of your body) and drains your bladder. Your doctor or nurse will teach you how to put it in and take it out. Indwelling catheter (also called a Foley catheter). This kind stays put. A tiny balloon filled with water keeps one end inside your bladder. The other end drains out into a bag that's either strapped to your leg or hanging from the side of a bed or a stand. An indwelling catheter needs to be replaced at least every 3 months or so. Suprapubic catheter. Your doctor puts this type into your bladder through a cut in your belly, a little below your belly button. It's typically more comfortable than an indwelling catheter and isn't as likely to give you an infection. Condom catheter. This may be an option for some men. Nothing goes into your bladder. Instead, a sheath similar to a condom fits around your penis. A tube takes the urine from there into a bag. It may seem more comfortable than other types of urinary catheters, but it can slip or leak. There are a few things to watch for when you use any type of urinary catheter. Infection. This is the most common problem. The catheter may let germs into your body, where they can infect your bladder, urethra, or kidneys. Call your doctor if you: Feel pain in your belly or groin Have a fever or chills Feel suddenly confused Leaks. This may be a sign that your catheter is blocked by clotted blood or debris, which is common with indwelling catheters. Tell your doctor if you see blood clots in your urine or you think something is blocking the flow of urine. Bladder spasms. These can happen if your bladder tries to push out the catheter. Medicine can help. These give you medicine or fluids straight into your bloodstream. It's also called an IV. There are two kinds: Peripheral venous catheter. If you need an IV for a short time, you'll probably have this type, which is connected to a vein in your hand, forearm, or foot. This is the simplest, least expensive kind. It can stay in up to 4 days before your nurse has to replace it. If it's there longer, it might irritate your vein or cause other problems. This may not be the right kind of catheter for you if: You'll need medicine more than a few days. You're not in the hospital, but instead go to your doctor's office or hospital when it's time for a dose. Central venous catheter. If you need medicine for a longer time, you'll probably get this type of catheter, which goes into your neck, leg, arm, or the top of your chest and is connected to one of the large blood veins that go in and out of your heart. It can stay in for months or even years. Your doctor might recommend one if: You'll need intravenous medicine for a long time. A large vein can handle a catheter better than a small one. If you need chemotherapy, you'll probably have this kind of catheter. You'll get IV medicine as an outpatient. These catheters are less likely to come out, so you can be more active between treatments. You need a lot of medicine or blood quickly. Your doctor wants to measure the blood pressure in one of your large veins. Your doctor needs samples of your blood several times a day. With this, the nurses don't have to keep sticking you with a needle. You can't take in food through your mouth, stomach, or intestines, so the nutrients have to go directly into your blood. Your kidneys aren't working right. To take their place, your medical team will connect you to a dialysis machine, which cleans the waste material out of your blood. You need medicine that might hurt your skin or muscles if it leaks out. That's not as likely to happen with this kind of catheter. To put in the catheter, your medical team probably won't put you to sleep, but they will give you medicine to relax you and make you sleepy. And they'll numb the area where they'll put the catheter in. There's a related kind of catheter called a peripherally inserted central catheter ( PICC). It goes in near your elbow and runs up through a vein in your arm. When your medical team puts a central venous catheter in, there's a small chance of a few issues: The catheter might injure the vein. Blood might leak out and cause a bruise or other problems. In most cases, the bleeding stops on its own. The catheter might cut your lung, which would make it collapse. If that happens, your medical team can reinflate your lung. Your heart might go off its normal rhythm. If so, it usually returns to normal by itself. When your catheter stays in for a while, other problems might crop up: The catheter might leak. Be careful when you handle the part outside your skin. The catheter might get twisted. Your nurse or doctor may have to straighten or replace it. Clotted blood might block your catheter. Your nurse will show you how to flush it out to help prevent that. The catheter might come loose from the vein. If the catheter is sticking farther outside of your skin than usual, that's a sign that this has happened. Your nurse or doctor will need to fix it. You might get an infection where the catheter goes in through your skin. That's less likely if you keep the catheter and the skin around it clean. Redness, tenderness, or swelling can be signs of infection. So can a fever or chills. A blood clot might form in the vein, or the vein might get narrow. Your medical team will watch you carefully for these issues.