A male urinary catheter is a flexible, hollow tube designed to drain urine directly from the bladder. This medical device is introduced when an individual cannot empty the bladder naturally, often due to retention or a medical procedure. Catheters may be required for a short period, such as following surgery, or for long-term management of chronic conditions.
The Basic Structure and Materials
The physical structure of an internal male catheter consists of a long, slender tube, typically around 16 inches in length to accommodate the male urethra. The insertion tip, which enters the body, is often tapered for easier placement. This tip contains small openings called drainage eyes, which are the portals through which urine enters the tube from the bladder.
The opposite end features a funnel connector or drainage port, which facilitates urine collection. This funnel connects to a urine collection bag or allows urine to drain into a receptacle. Catheters are manufactured from materials like silicone, latex, and polyvinyl chloride (PVC). Silicone models are often transparent and flexible, while PVC options may appear opaque or frosted and are slightly more rigid.
The material choice affects the catheter’s texture and flexibility. Some catheters feature a pre-lubricated or hydrophilic coating, giving the device a noticeably slippery or wet appearance when activated with water. While most tips are straight, some designs incorporate a slight curve, known as a coudé tip, which aids in navigating past blockages or an enlarged prostate.
Differentiating the Main Types
The appearance of a male catheter varies based on its intended use. The indwelling catheter, commonly known as a Foley catheter, is visually distinct due to a balloon mechanism located near its insertion tip. Once inside the bladder, a small channel is used to inflate this balloon with sterile water, securing the device for continuous drainage. This type remains in the bladder for an extended period and is always connected to a collection bag.
In contrast, the intermittent or straight catheter is a single-use hollow tube. It lacks the inflation port and retention balloon of the indwelling type, presenting only a straight, flexible shaft. This device is inserted to empty the bladder and then immediately removed, functioning as a standalone device unconnected to a long-term drainage bag.
The external catheter, sometimes called a condom or Texas catheter, does not enter the body. This device is a sheath or sleeve that rolls over the penis, similar to a condom, and is held in place with an adhesive or strap. A short tube extends from the sheath to a collection bag, making it a non-invasive option used for managing urinary incontinence.
Understanding Catheter Sizing
The size of a catheter tube is determined using the French (Fr) scale, a universal system for measuring the device’s outer diameter. Each French unit is equivalent to one-third of a millimeter; thus, a larger French number indicates a wider catheter. For example, a 16 Fr catheter is visibly thicker than a 12 Fr catheter, which affects the flow rate of urine.
The French size is often indicated by a standardized color-coding system on the funnel connector. For instance, a 14 Fr catheter might have a green funnel, while an 18 Fr catheter is identifiable by its red funnel, providing a quick visual reference. Adult male catheters generally range from 12 Fr to 24 Fr, with the most common sizes being between 14 Fr and 18 Fr.
While the diameter is standardized, the length of the catheter tube also varies to suit different anatomies. Standard male-length catheters are typically about 16 inches long to accommodate the longer male urethra. Shorter, more compact designs, such as pocket catheters, are also available for increased discretion and portability.