An intermittent catheter is a thin, flexible tube you insert through your urethra into your bladder to drain urine, then remove right away. Unlike an indwelling (Foley) catheter that stays in place for days or weeks, an intermittent catheter goes in, empties the bladder, and comes back out, typically every four to six hours throughout the day. It’s the preferred method of bladder drainage for many people who can’t fully empty their bladder on their own.
How Intermittent Catheterization Works
The process is straightforward. You wash your hands, lubricate the catheter tip (unless it comes pre-lubricated), and gently guide it through the urethra until urine begins to flow. The urine drains into a toilet or a collection container. Once the flow stops and your bladder is empty, you slowly withdraw the catheter and either dispose of it or clean it for reuse, depending on the type.
Most people catheterize four to six times a day, roughly matching the schedule of normal urination. The goal is to keep your bladder from overfilling, which can cause kidney damage or leakage. Your healthcare provider will recommend a frequency based on how much fluid you take in and how much urine your bladder holds comfortably.
This approach mimics the natural cycle of filling and emptying, which is one reason it’s favored over leaving a catheter in permanently. There’s no drainage bag strapped to your leg, no tubing to manage between uses, and more freedom to move through your day normally.
Who Needs an Intermittent Catheter
Intermittent catheterization is the standard approach for people with temporary or permanent difficulty emptying their bladder. The most common reason is neurogenic bladder, where nerve damage disrupts the signals between the brain and bladder. This happens with spinal cord injuries, multiple sclerosis, spina bifida, stroke, and some complications of diabetes.
It’s also used after certain surgeries when the bladder needs time to recover normal function, or for people with conditions that physically block urine flow. Some people use intermittent catheters for a few weeks while healing. Others rely on them for the rest of their lives. In either case, most people learn to do it themselves at home without assistance.
Types of Intermittent Catheters
There are three main categories, and the differences come down to coating and packaging.
- Uncoated catheters are the most basic type, usually made of PVC (a flexible plastic). You apply a separate lubricant before inserting them. Some uncoated catheters are designed to be washed and reused over several days, while others are single-use and disposable.
- Hydrophilic-coated catheters have a special polymer coating that becomes slippery when activated with water. Because the lubrication is built into the surface of the catheter, insertion tends to be smoother. A large meta-analysis found that hydrophilic catheters were associated with a 16% lower risk of urinary tract infections compared to standard uncoated catheters.
- Closed-system catheters come pre-lubricated inside a self-contained kit that includes a collection bag. Everything stays sealed until you’re ready to use it, which reduces the number of surfaces you touch during the process. These are often used in settings where a clean bathroom isn’t available.
Catheter Sizing
Catheters are measured using the French scale, where higher numbers mean a larger diameter. The right size needs to be wide enough for urine to drain efficiently but narrow enough for comfortable insertion.
Babies and infants typically use the smallest sizes, around 5 or 6 French. Children and adolescents generally fall in the 8 to 12 French range. For adults, women most commonly use 12 to 16 French, while men typically use 14 to 18 French, though sizes range from 12 up to 24 French depending on individual anatomy.
Most catheters with funnel ends use a universal color-coding system, so each French size has a specific funnel color. This makes it easy to grab the right catheter quickly, especially if you keep several in your bag or bathroom.
Risks and Complications
Urinary tract infections are the most common complication. Bacteria can be introduced each time a catheter is inserted, and recurrent UTIs are a reality for many long-term users. Choosing hydrophilic catheters, maintaining clean technique, and staying well-hydrated all help reduce that risk.
One concern people often have is whether intermittent catheterization is safer than an indwelling catheter in terms of infection. A study comparing the two approaches in over 500 patients found that UTI rates were virtually identical at 8% for both groups at a single visit, with no significant difference in the number of infections over the prior 12 months either. The advantage of intermittent catheterization isn’t necessarily a dramatic drop in infections. It’s the avoidance of other complications that come with long-term indwelling catheters, like bladder spasms, urethral erosion, and bladder stones.
Urethral trauma is another possibility. Repeated insertion can irritate or scratch the urethral lining, sometimes causing blood in the urine. Over many years, this repeated friction can contribute to urethral strictures, where scar tissue narrows the passage. Using well-lubricated catheters and the correct size helps minimize this.
What Daily Life Looks Like
Most people find the first few self-catheterizations intimidating, but the technique becomes routine quickly. A typical day involves catheterizing four to six times: when you wake up, a couple of times during the day, and before bed. Each session takes only a few minutes once you’re comfortable with the process.
Portability is one practical consideration. Single-use catheters come individually wrapped and are small enough to carry in a purse, backpack, or pocket. Some people keep supplies in their car, at work, and at home so they’re never caught without one. Closed-system kits are bulkier but useful when you’re somewhere without easy access to a sink.
Fluid management plays a role too. Drinking a consistent amount throughout the day, rather than large amounts at once, keeps your bladder from overfilling between catheterizations. Many people learn to time their fluid intake around their schedule to make the process more predictable.