Meningococcal disease is a serious bacterial infection caused by the bacterium Neisseria meningitidis. It can lead to meningitis, an inflammation of the protective membranes covering the brain and spinal cord, and septicemia, a bloodstream infection. Symptoms may include fever, headache, stiff neck, and a rash. This disease spreads through respiratory droplets and close contact with an infected person. Vaccines are available to help prevent certain strains of meningococcal disease, making vaccination important, especially for adolescents and young adults. Early diagnosis and treatment are crucial for improving outcomes.