Difficulty breathing, also known as dyspnea, is a condition where a person feels short of breath or struggles to breathe normally. This can occur due to various reasons, including asthma, allergies, or lung infections. It may feel like you can't get enough air, or that breathing requires more effort than usual. In some cases, difficulty breathing can be a sign of a serious medical issue, such as pneumonia or heart problems. If someone experiences severe or sudden difficulty breathing, it is important to seek medical attention immediately, as it can be life-threatening.