Underwire bras are often discouraged for long-term wear or specific situations like air travel and medical procedures due to physical discomfort and health-related nuances. From a comfort perspective, the rigid metal or plastic wire can dig into the ribcage or breast tissue, especially when sitting for long periods (like on a long-haul flight) or during hormonal fluctuations when breasts are more sensitive. In terms of health, some experts suggest that poorly fitted underwires can compress the lymphatic system around the breast, potentially hindering natural fluid drainage, though this is a subject of ongoing debate. For travelers, underwire bras are a frequent "false positive" for airport security scanners, leading to invasive pat-downs. Additionally, during medical imaging like MRIs or certain X-rays, the metal wire can interfere with the results or cause safety issues. In 2026, the fashion industry has seen a massive shift toward "wireless" or "unlined" bras and "bralettes" that use advanced fabric engineering to provide support without the need for a structural wire, prioritizing skin health and unrestricted movement over rigid shaping.