Young syndrome is a condition characterized by male infertility, damaged airways in the lungs (bronchiectasis), and inflammation of the sinuses (sinusitis). Male infertility in Young syndrome is secondary to obstructive azoospermia, a condition in which sperm are produced but do not mix with the rest of the ejaculatory fluid, due to a physical obstruction in the epididymis (tube through which sperm exit the testis). This results in nonexistent levels of sperm in semen.

Young syndrome is typically diagnosed in middle-aged men who undergo evaluation for infertility. As the signs and symptoms of Young syndrome are similar to cystic fibrosis (CF), part of the diagnosis process may include ruling out CF. Although the exact cause of Young syndrome has not been identified, it is believed to either be related to childhood exposure to mercury or genetic factors. While there is no one treatment for Young syndrome, management involves treatment of sinus and lung infections. Fertility treatment may also be an option, including surgery to remove the obstruction in the epididymis (vasoepididymostomy) or assisted reproduction, such as intracytoplasmic sperm injection (ICSI).