Süstleid

Süstleid are slender, hollow instruments used with syringes to deliver medications, withdraw fluids, or perform diagnostic procedures. They are typically made of medical-grade stainless steel and are designed for single use in sterile packaging to minimize infection risk. Needles differ by length, gauge (diameter), bevel shape, and hub design, and they are selected according to the injection site, medication viscosity, and patient factors. In general, longer needles are used for intramuscular injections, while shorter needles are common for subcutaneous injections; gauge numbers indicate thickness, with smaller numbers corresponding to thicker needles.

Manufacturing focuses on precision, sterility, and sharpness. Needles are sterilized before packaging and marketed as disposable devices. Safety considerations have led to the development of features such as shielded or retractable designs to reduce needlestick injuries. Coatings and lubricants may be applied to ease penetration and improve patient comfort.

In clinical practice, needle selection also depends on the administration route—subcutaneous, intramuscular, intradermal, or intravenous approaches—and on the characteristics of the medication, such as viscosity and required delivery rate. Proper technique, including correct angle of insertion and depth, is essential for efficacy and safety.

Historially, the modern hypodermic needle emerged in the mid-19th century through the work of Charles Pravaz and Alexander Wood, enabling widespread systemic administration of medicines. Since then, needle design has evolved to enhance safety, reduce pain, and accommodate a range of therapeutic applications. Disposal of used needles requires approved sharps containers and adherence to local regulatory guidelines to prevent injuries and contamination. See also: syringes, needles, needlestick injuries.