Fissures are narrow openings or cracks that can occur in various materials, including rocks, soil, and even human skin. In geology, fissures often form due to tectonic activity, where the Earth's plates shift and create gaps. These cracks can vary in size and depth, influencing the landscape and ecosystems around them. In medicine, a fissure refers to a split or tear in the skin or mucous membranes, commonly found in areas like the anus or mouth. These fissures can be painful and may result from conditions such as constipation or inflammatory bowel disease. Treatment often involves improving hygiene and using topical medications.