The four main types of urinary catheters are indwelling (Foley) catheters, intermittent catheters, suprapubic catheters, and external catheters. Each type drains urine from the bladder using a different approach, and the right choice depends on how long drainage is needed, the underlying medical condition, and the patient’s anatomy.
Indwelling (Foley) Catheters
An indwelling catheter, commonly called a Foley catheter, is a flexible tube inserted through the urethra and left in place for days or weeks at a time. What keeps it from sliding out is a small balloon near the tip that inflates inside the bladder. The standard balloon is filled with 10 mL of sterile water after insertion. Larger balloons (30 mL) exist but aren’t generally recommended because they increase the amount of urine that pools at the bottom of the bladder, raising the risk of infection and irritation.
Foley catheters connect to a drainage bag that collects urine continuously. They’re used after surgery, during critical illness, or when someone can’t empty their bladder on their own for an extended period. The main drawback is infection risk: the longer a Foley stays in, the higher the chance of developing a catheter-associated urinary tract infection. That’s why healthcare teams aim to remove them as soon as they’re no longer strictly necessary.
Intermittent Catheters
An intermittent catheter is a thin, straight tube that you or a healthcare provider inserts through the urethra, drains the bladder, and then removes right away. The entire process takes a few minutes. Because nothing stays inside the body between uses, this approach is generally performed multiple times a day, typically four to six times depending on fluid intake and bladder capacity.
Intermittent catheterization is the go-to method for people with spinal cord injuries, neurological conditions, or other problems that prevent the bladder from emptying naturally on a long-term basis. Urinary tract infections remain the most common complication, affecting roughly 50 to 60 percent of regular users in a given year based on German health claims data. That rate is still lower than what’s seen with indwelling catheters left in place continuously, which is one reason clinicians prefer intermittent use whenever the person is able to manage the routine.
Intermittent catheters come in two broad material categories. Uncoated versions are made from PVC, silicone, or latex and typically require a separate lubricant. Hydrophilic-coated catheters have a slippery polymer layer designed to reduce friction during insertion, which may lower the chance of urethral irritation over thousands of insertions. Studies comparing the two haven’t shown a dramatic difference in bleeding episodes, but many long-term users prefer the feel of hydrophilic models.
Catheter Length and Tip Variations
Catheters are manufactured in two standard lengths: 20 to 26 cm for female anatomy, and 40 to 45 cm for male anatomy. The shorter female-length catheter should never be used in males, as it may not reach the bladder and can cause injury.
Most intermittent catheters have a straight tip, but a curved-tip version called a Coudé catheter exists for men with an enlarged prostate. The slight upward bend at the end helps navigate the sharper angle created by prostate tissue. In one study across two hospitals, 41 to 54 percent of patients who couldn’t be catheterized with a standard straight tip were successfully catheterized simply by switching to a Coudé.
Suprapubic Catheters
A suprapubic catheter bypasses the urethra entirely. Instead, it enters the bladder through a small surgical opening in the lower abdomen, roughly two finger-widths above the pubic bone. The procedure requires a minor incision, and the catheter is then secured in place and connected to a drainage bag, similar to an indwelling Foley.
This type is used when the urethra is damaged, blocked, or needs to be left alone to heal. It’s also a common long-term option for people who need continuous drainage for months or years. Compared with urethral catheters, suprapubic catheters are easier to change, associated with fewer urinary tract infections, require antibiotics less often, and are generally considered more comfortable for men with long-term catheter needs. The tradeoff is that the initial placement is a surgical procedure, and the abdominal site needs regular cleaning to prevent skin infection around the opening.
External Catheters
External catheters don’t enter the body at all. They fit over or around the genitalia and funnel urine into a collection bag. Because nothing is inserted into the urethra or bladder, the infection risk is the lowest of all four types.
The most common version for men is the condom catheter, a soft sheath (usually silicone) that rolls over the penis and connects to a drainage tube at the tip. These come in self-adhering models with built-in adhesive or non-adhesive versions that rely on external tape or straps. Pressure-sensitive silicone adhesive is one newer approach: it bonds gently to the skin and slowly loosens over time as the skin perspires. If the catheter starts slipping, a few drops of adhesive or gentle pressure can restore the seal.
Proper fit matters more than it might seem. A condom catheter that’s too tight can restrict blood flow, and one that’s too loose will leak. Keeping the penile skin clean and dry between changes helps prevent moisture-related skin breakdown. Staff in hospital settings sometimes wrap adhesive tape around the catheter and penis to keep it secure, but this practice increases the risk of skin injury and should be avoided. The drainage tubing also needs to run freely to the collection bag without kinks, since any backup of urine against the skin causes irritation.
External options for women are less common but do exist. Female external catheters use a soft adhesive cup or pad that sits over the urethral opening and pubic area, directing urine into a drainage line. They work best for managing incontinence rather than for medical conditions that require precise measurement of urine output.
Choosing the Right Type
The decision between these four types comes down to a few practical questions: how long drainage is needed, whether the person can perform self-catheterization, and whether there’s a reason to avoid the urethra. For short-term hospital use, indwelling Foley catheters are the default. For people managing a chronic bladder condition at home, intermittent catheterization offers the best balance of independence and lower infection risk. Suprapubic catheters fill the gap when long-term drainage is necessary but the urethra isn’t a viable route. And external catheters work well for incontinence management in people whose bladders empty on their own but who can’t get to a toilet reliably.
Each type also comes in multiple French sizes (a measurement of the tube’s outer diameter). A larger number means a wider tube. Most adults use something in the 12 to 18 French range, with the specific size chosen based on anatomy and the reason for catheterization.